Standards Border Templatedownloads.semi.org/web/wstdsbal.nsf... · Web viewThis guide describes how to construct a specified model edge profile from parameters of six model edge segments,

Background Statement for SEMI Draft Document 4428A [EP7]New Standard: GUIDE TO SPECIFYING EDGE PROFILE OF SILICON WAFERSNote: This background statement is not part of the balloted item. It is provided solely to assist the recipient in reaching an informed decision based on the rationale of the activity that preceded the creation of this document.

Note: Recipients of this document are invited to submit, with their comments, notification of any relevant patented technology or copyrighted items of which they are aware and to provide supporting documentation. In this context, “patented technology” is defined as technology for which a patent has issued or has been applied for. In the latter case, only publicly available information on the contents of the patent application is to be provided.

The SEMI Edge Profile WG, within the SEMI International Advanced Wafer Geometry TF of the Global Silicon Wafer Committee, is developing the following document. Edge profile is not so easy to express its characteristics using a simple terminology since it consists of several segments and, more over, segments of real wafers are not simple straight line or circle. General terminology covers variety of the edge related terms such as non-linear and non-circular edge segments. Model edge profile consisting of straight apex, straight bevel and circular shoulder is simple for any discussions and useful for specification since it is independent of test method. A specified model edge profile consists of the model edge segments using their specified parameters and tolerance. New template is an area around the specified model edge profile defined by specified distance as acceptable deviation from the specified model edge profile. It is tighter than current SEMI M1 template. Tolerance of the individual parameters is for acceptable deviation of measured parameters from the specified values. Over view is a quick reference of model edge profile and its specification table.

General terminology was proposed as a separate document that is known as EP1 among the WG members. Tighter template based on model edge profile was proposed as a separate document that is known as EP2 among the WG members. Both documents were dealing with test method independent terminology and edge profile. At the Boston meeting in 2007, consensus was to separate the test method independent documents and the test method documents. EP1 and EP2 tried to combine as a single document but there was some contradiction even though both were test method independent. General terminology was broad enough to include any shape of the edge segments. On the other hand, model edge segments were strictly straight line and circular arc. Hierarchical structure was introduced to solve this contradiction. It is “Edge profile architecture” as appendix 1 in this standard. It makes position of all documents clear. Tree of edge segments and parameters illustrates correlation of various aspects of the edge segments. General terminology in this document is common to model edge profile and test method. Terminology in test method is imported, as much as possible, as general terminology to avoid any confliction among documents. Terminology specific to test method is not included because of its locality.

In addition, Doc. 4280, NEW STANDARD: TEST METHODS FOR EXTRACTING RELEVANT CHARACTERISTICS FROM MEASURED WAFER EDGE PROFILES, is under development in the SEMI International Edge Profile WG (EPWG). This document is also balloted in cycle 3 of 2008.

The ballot results will be reviewed by the EPWG, and the International AWG TF and adjudicated by Silicon Wafer Committee during their meetings in conjunction with the SEMICON West in San Francisco, July 15-17, 2008.

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Informational (Blue) Ballot1000A

SEMI Draft Document 4428A [EP7]NEW STANDARD: GUIDE TO SPECIFYING EDGE PROFILE OF SILICON WAFERS

1 Purpose1.1 This standard provides a guide to specifying model edge profiles using model edge segments and their parameters that are simple straight line and circle independent of the test method. Tolerance is either of two ways: by template or by individual parameter’s tolerance. These methods provide more definitive edge profile specification than current SEMI M1 template.

1.2 SEMI M1 specifies the edge shape of silicon wafers by using templates that allow a wide variation of edge profiles in conforming wafers manufactured by silicon suppliers. M1 is still used as a specification for some applications. However, many users of silicon wafers have recently found that tighter tolerance of the edge profile is necessary for improved production of devices. This guide is to improve M1 template.

2 Scope2.1 To make understanding and discussion of edge profile clear, a simple model edge segments consisting of straight line and circular arc are introduced. A general terminology is dealing with non-linear and non-circular edge profile, while the other is specific to the simple straight and circler segments are necessary for the model edge segments. The later is local and its exact definitions are applied only in model edge profile section. Test method specific matter is in the other documents.

2.2 This guide describes how to construct a specified model edge profile from parameters of six model edge segments, that are front/back bevels, front/back shoulders and front/back apexes, and front/back edge widths. Eight parameters in total from a specification table are used to construct it. These parameters are independent of the edge profile test method but are constrained by the nominal wafer thickness. Edge profile is specified by these parameters and specification table is provided to fill them in.

2.3 This guide also describes construction of a template, as a tolerance, that is a specified area for acceptable deviation from the specified model edge profile. The template can be used to determine whether the measured profile is within the specification. This guide also provides a way to specify tolerances of individual parameters of the specified model edge profile. These individual tolerances can be used to determine whether the measured parameters are within the specification.

2.4 Terminology structure is described in Appendix 1 in detail. Tree of edge profile and segments illustrates all segments’ parameters that are slightly different among model edge profile and test methods.

NOTICE: This standard does not purport to address safety issues, if any, associated with its use. It is the responsibility of the users of this standard to establish appropriate safety and health practices and determine the applicability of regulatory or other limitations prior to use.

3 Overview3.1 Edge profile of real wafer consists of several segments that are not simple straight line or circle. On the other hand, model edge profile consists of simple straight line or circular arc segments that are independent of test method algorism and it is useful for any discussions and specifying the edge profile. Segments of model edge profile, their parameters and template are briefly shown here in addition to specification tables for the model edge profile.

3.1.1 Segments of edge profile, their parameters and template

3.1.1.1 Edge profile consists of six straight line or circular arc segments as shown in Figure 1(a). Template, Figure 1(b), is an area for the acceptable deviation from the specified model edge profile. Parameters are numerical properties of the segment and usually expressed as bevel angle, shoulder radius and apex length. These parameters together with the edge width, as shown in Figure 2, are used to specify the model edge profile. Edge width is not a parameter but is common specification numeric. Wafer thickness constrains parameters including edge width. Their vertical sum must equal to the nominal wafer thickness. If not, adjust some of them.

This is a draft document of the SEMI International Standards program. No material on this page is to be construed as an official or adopted standard. Permission is granted to reproduce and/or distribute this document, in whole or in part, only within the scope of SEMI International Standards committee (document development) activity. All other reproduction and/or distribution without the prior written consent of SEMI is prohibited.

Page 1 Doc. 4428A SEMI

Semiconductor Equipment and Materials International3081 Zanker RoadSan Jose, CA 95134-2127Phone:408.943.6900 Fax: 408.943.7943

DRAFTDocument Number: 4428A

Date: April 21, 2008

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(a) Segments of model edge profile (b) Template for specified model edge profile

Tolerance

Specified Model Edge Profile

TemplateTolerance


Template

Front

Bevel

Back Bevel

Fron

t Sh

ould

er

Back Shoulder

Fron

t A

pex

Bac

k A

pex

(Front Surface)

(Back Surface)

Front

Bevel

Back Bevel

Fron

t Sh

ould

er

Back Shoulder

Fron

t A

pex

Bac

k A

pex

(Front Surface)

(Back Surface)

(a) Segments of model edge profile (b) Template for specified model edge profile

Tolerance


TemplateTolerance


Template

Front

Bevel

Back Bevel

Fron

t Sh

ould

er

Back Shoulder

Fron

t A

pex

Bac

k A

pex

(Front Surface)

(Back Surface)

Front

Bevel

Back Bevel

Fron

t Sh

ould

er

Back Shoulder

Fron

t A

pex

Bac

k A

pex

(Front Surface)

(Back Surface)

Figure 1Segments of edge profile (a) and template (b). These segments are constituents of the model edge profile and

they are straight front/back bevel, circular front/back shoulder and straight front/back apex. Combined front and back apex can be called simply apex. Front/back surface that defines starting points of the edge profile is

not a part of the edge profile. Template is, as a tolerance, an area where the specified model edge profile is widen by to accept any deviation from the specified model edge profile.

Front Bevel Angle

Back Bevel Angle

Fron

t A

pex

Leng

thB

ack

Ape

x Le

ngth

Front Edge Width

Back Edge Width

Front Shoulder

Radius

Back Shoulder

Radius

(Waf

er T

hick

ness

t)

Wf0

Wb0

Rf 0

R b0

b0

f0

L f0

L b0

Front Bevel Angle

Back Bevel Angle

Fron

t A

pex

Leng

thB

ack

Ape

x Le

ngth

Front Edge Width

Back Edge Width

Front Shoulder

Radius

Back Shoulder

Radius

(Waf

er T

hick

ness

t)

Wf0

Wb0

Rf 0

R b0

b0

f0

L f0

L b0

NOTE 1: Symbol’s subscript, f or b, means front or back and superscript 0 is for model edge parameters. If superscript is 1 or 2, it is for test method 1 or 2. These are details of parameters. When f or b is omitted, it does not concern the surface, that is, it

applies to parameters of both surfaces. When 0 is omitted, it does not care about model edge profile or test method. Denoting of f, b, 0, 1and 2 by subscript or superscript is arbitrary.

Figure 2Parameters combined with surface (front or back) and segment (shown in Figure (a)). Parameters that are

numeric are front/back bevel angle, front/back shoulder radius and front/back apex length. Front/back edge width is not a parameter but has a similar distance property as illustrated in the figure. Parameter symbols

are also included here for identifying the parameters uniquely.






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Informational (Blue) Ballot1000A3.1.2 Specification table

3.1.2.1 For specifying the model edge profile, table 1 contains parameters with segments and surface. Their additional properties are symbols for each parameter and its unit. Specification column is just to fill the specification numeric. For tolerance, two tables are provided. One is template and the other is list of tolerance of individual parameters to be used as a measure of acceptable scattering of the parameter.

3.1.2.1.1 (a) Parameters

3.1.2.1.1.1 Table 1 (a) is used as a specification table by filling numeric in the specification column.

3.1.2.1.1.2 Specification table is to fill the specification numeric of the parameters of the model edge segments in the specification column. Parameters are listed with its symbol and unit. Subscript f or b of symbol is for parameters of front or back segments. Superscript 0 means segments and their parameters are of the model edge profile. Edge width does not have its corresponding segment as shown in Figure 2.

Table 1 (a) Parameters of specified model edge profile

3.1.2.1.2 (b) Tolerance

3.1.2.1.2.1 Two tables are provided for the tolerance specification.

3.1.2.1.2.1.1 (b-1) Template

3.1.2.1.2.1.1.1 Template as a tolerance is an acceptable area around the segment of the model edge profile.

3.1.2.1.2.1.1.2 Template is around the segments to accept any scattering of the edge profile.

Table 2 (b-1) Template as a tolerance of the model edge profile

3.1.2.1.2.1.2 (b-2) Individual parameter tolerance

3.1.2.1.2.1.2.1 Tolerance of individual parameter is a measure of acceptable scattering of the individual parameter.

3.1.2.1.2.1.2.2 Tolerance of the individual parameters is specified when the tolerances for some parameters are needed separately as a measure of their acceptable range. For example, Wf

0 is a measure of acceptable edge width range.






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Informational (Blue) Ballot1000ATable 3 (b-2) Tolerance of the individual parameters.

4 Limitation4.1 This guide does not define the technique or equipment used to acquire measured edge profiles nor does it describe how to assess the capability of equipment for measuring edge profiles or how to extract from measured profiles.

4.2 This standard refers explicitly to silicon wafers, but may also be applied to wafers consisting of other materials.

5 Referenced Standards and Documents5.1 SEMI Standards

SEMI M1 — Specification for Polished Monocrystalline Silicon Wafers

SEMI M20 — Practice for Establishing a Wafer Coordinate System

SEMI M59 — Terminology for Silicon Technology

NOTICE: Unless otherwise indicated, all documents cited shall be the latest published versions.

6 General Terminology6.1 General terms, acronyms, abbreviations and symbols associated with silicon technology and used in this standard are listed and defined in SEMI M59. The definitions specifically related to edge profiles that are given in SEMI M59 include back surface, edge profile, front surface, and thickness.

6.2 Other Terminology Related to Edge Profile.

6.2.1 apex — the blunt, but not necessarily linear, region of the edge profile, oriented approximately perpendicular to the reference line and located between the front and back shoulder regions.

6.2.2 apex angle ― the angle between the z-axis and the front or back apex region; the sign of the apex angle is positive if the q-coordinate increases with increasing magnitude of |z| (see Note 1).

6.2.3 apex length — the distance along the z-axis between the front and back shoulders of the edge profile, usually divided into two distances from the reference line to the front and back shoulders (see Note 1).

6.2.4 bevel — the region of the edge profile located between the surface line and the shoulder.

6.2.5 bevel angle ― the angle between the median plane and the front or back bevel of the edge profile. (see Note 1).

6.2.6 center-referenced (adj.) — property of a measurement, calculation, or coordinate system with the position established using the wafer center as the origin, such as in the wafer coordinate systems of SEMI M20.

6.2.7 edge, of a silicon wafer — the annular region of the wafer from the periphery inward that has been intentionally shaped chemically or mechanically to form the edge profile.

6.2.8 edge profile — a line consisting of front bevel, front shoulder, front apex, back apex, back shoulder and back bevel (see M59).

6.2.9 edge-referenced (adj.) — property of a measurement, calculation, or coordinate system with the position established using the periphery of the wafer as the origin.






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Informational (Blue) Ballot1000A6.2.10 edge width — the distance inwardly from the periphery of the wafer, to the end of the edge profile (see Note 1).

6.2.11 facet — not preferred, use edge.

6.2.12 facet length — not preferred, use edge width.

6.2.13 measured edge profile — a finite array of q, z points representing the cross-sectional view of a wafer edge profile that is acquired by a measurement system.

6.2.14 model edge profile — a basic type of wafer edge profile. a wafer edge profile with segments consisting only of straight lines (apex and bevel), and circular arcs (shoulder) in the cross-sectional view. Its parameter is independent of test method since it is not related to any algorism to extract it from the measured data.

6.2.15 near-edge region — the annulus of the wafer between the inner boundary of the edge (inner end of the edge profile) and the outer region of the fixed quality area. The near-edge region may stop at the outer boundary of the FQA or extend a small distance into the FQA depending on the context.

6.2.16 parameter, of an edge profile segment — characteristic of the segment (length, angle, or radius). .

6.2.17 profile transition, of a silicon wafer — the region of the wafer where the front or back surface meets the edge.

6.2.18 q-axis — the reference line in the cross-sectional view of the edge of the wafer with the origin at the intersection of the reference line and the wafer periphery and the positive direction toward the wafer center

6.2.19 reconstructed edge profile — an edge profile constructed by using the parameters extracted from the measured edge profile.

6.2.20 reference line — the line, midway between the front and back surface lines, that represents the median plane in the cross-sectional view of the edge of the wafer; it is the q-axis of the q-z edge-referenced coordinate system of that cross-sectional view.

6.2.21 segment — constituents of edge profile that are apex, shoulder and bevel.

6.2.22 shoulder — the curved region of the edge profile between the bevel and the apex.

6.2.23 shoulder radius — the radius of a circle representing the shoulder (see Note 1).

6.2.24 surface line — a line in the cross-sectional view of the edge of the wafer representative of the front or back wafer surface beyond a specified points on the edge profile.

6.2.25 template — an area to accommodate an acceptable deviation from the specified model edge profile.

6.2.26 z-axis — the line perpendicular to the reference line passing through the periphery of the wafer in the cross-sectional view of the edge of the wafer with origin at the intersection of the periphery and the reference line and the positive direction toward the front surface of the wafer.

NOTE 2: This term is a parameter; measured values of parameters depend on the test method algorism. When it is used in the test method standards, it should be defined exactly in the test method procedure.

7 Model edge profile 7.1 The model edge segments are straight bevel, circular arc shoulder and straight apex. It differs from any other profiles consisting of non-linear line or non-circular arc, like measured profile or actual wafer edge shape. Following exact definitions are only applicable to the model edge segments, their parameters and the specified model edge profile using them.

7.1.1 Model edge profile types

7.1.1.1 model edge profile — a basic concept of wafer edge profile. Its segments consist of only straight apex, straight bevel, and circular arc shoulder and reference points in between them. These segments are independent of test method algorism by definition. This is useful, in general, for any edge profile discussion.

7.1.1.2 specified model edge profile — an actual wafer edge profile constructed by the model edge segments using the specified parameters and edge widths that is not a parameter of a segment but has a parameter like numerical






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Informational (Blue) Ballot1000Avalue. These parameters and edge width are independent of test method since they are not related to any algorism to extract them from the measured data. This is useful for specifying edge profile independent of test method algorism.

7.1.1.3 template — an area around the specified model edge profile for acceptable deviation from the specified model edge profile.

7.1.1.4 individual parameter tolerance — tolerance of some individual parameter, if it is needed, is a measure of acceptable range of the individual parameter.

Front Bevel Angle ｆ０

Back Bevel Angle ｂ０

Front Bevel

Back Bevel

L ｆ０

L ｂ０

Fron

t A

pex

Leng

th

Bac

k A

pex

Leng

thApe

x

Front Edge Width

Wｆ０

Back Edge Width

Wｂ０

q-Axis

z-Axis

Thic

knes

s t

Front Shoulder

Radius Rｆ０

Back S

hould

er

Radius R

ｂ０

Reference Line

Front Surface Line

Back Surface Line

A f0

B f0

C f0

Cb0

Bb0 Ab0

O

Fron

t Sho

ulder

Back Shoulder



Front Bevel

Back Bevel

L ｆ０

L ｂ０

Fron

t A

pex

Leng

th

Bac

k A

pex

Leng

thApe

x

Front Edge Width

Wｆ０

Back Edge Width

Wｂ０

q-Axis

z-Axis

Thic

knes

s t

Front Shoulder

Radius Rｆ０

Back S

hould

er

Radius R

ｂ０

Reference Line

Front Surface Line

Back Surface Line

A f0

B f0

C f0

Cb0

Bb0 Ab0

O

Fron

t Sho

ulder

Back Shoulder

NOTE 1: Symbol’s subscript, f or b, means front or back and superscript 0 is for model edge parameters. If superscript is 1 or 2, it is for test method 1 or 2. When f or b is omitted, it does not concern the surface, that is, parameters can apply to both of the

surfaces. When 0 is omitted, it does not care about model edge profile. Denoting of f, b and 0 by subscript or superscript is arbitrary.

NOTE 2: In this figure and in the other figures in this standard, the shape of the edge of the wafer is depicted as a cross section of the wafer perpendicular to the wafer surface along the circular circumferential part of the wafer edge with the q-axis positive

along a radius toward the center of the wafer and the z-axis positive toward the front surface of the wafer.Figure 3

Schematic drawing of a model edge profile segments, parameters, axes and other terms.

Segments are straight front/back bevel, circular front/back shoulder and straight front/back apex. Combined front and back apexes can be called simply apex. Front/back surface is not a part of the edge profile.

Parameters are front/back bevel angle, front/back shoulder radius and front/back apex length. Front/back edge width is not a parameter but has a similar distance property. Parameter symbols are also included here for identifying the parameters uniquely. Positions of reference points, Af0, Bf0, Cf0, Cb0, Bb0, Ab0 and origin

of the coordinate system O are shown.

7.1.2 Model edge profile coordinate systemCoordinate system is an edge referenced one independent of wafer diameter. Its origin is on the apex. 7.1.2.1 reference line — same as general reference line, simply, the median line between the front and back surface lines






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Informational (Blue) Ballot1000A7.1.2.2 q-axis — same as general q-axis but its origin is where the reference line intersects apex.

7.1.2.3 z-axis — same as general z-axis

7.1.2.4 back surface of model edge profile — a straight line representing a nominal wafer back surface.

7.1.2.5 front surface of model edge profile — a straight line representing a nominal wafer front surface.

NOTE 1: Although the front and back surfaces of the wafer are not formally the part of edge profile but they are needed to define the starting point of front bevel and the end point of back bevel. Nominal wafer thickness is a distance between them.

7.1.3 Reference points of model edge profile

Reference points, Af0, Bf0, Cf0, Cb0, Bb0 and Ab0 as illustrated in Figure 3 are obvious and independent of test methods.

7.1.4 Exact definition of segments of the model edge profileSegments of the model edge profile consist of following six segments as shown in Figure 3. NOTE 2: When front apex and back apex are combined as apex, then number of the segments is five in total.

7.1.4.1 front bevel of model edge segments— a straight line from Af0 to Bf0. It intersects front surface line by front bevel angle f

0. It is connected tangentially to front shoulder.

7.1.4.2 front shoulder of model edge segments — a circular arc, from Bf0 to Cf0 with front shoulder radius Rf0. It is

connected tangentially to front bevel and front apex.

7.1.4.3 apex of model edge segments— a straight line from Cf0 to Cb0 and perpendicular to the reference line. It is divided to the front apex (Cf0 to O) and the back apex (O to Cb0) at the origin (O) of the coordinate system. It is connected tangentially to front and back shoulders.

7.1.4.4 back shoulder of model edge segments — a circular arc, from Cb0 to Bb0 with back shoulder radius Rb0. It is

connected tangentially to back apex and back bevel.

7.1.4.5 back bevel of model edge segments — a straight line from Bb0 to Ab0. It intersects back surface line by back bevel angle b

0. It is connected tangentially to back shoulder.

7.1.5 Exact definition of segment’s parameter.Parameters are numerical properties of the segments. Specified model edge profile is constructed from segments using their numeric that are specification. Edge width is common specification numeric. Parameter symbol f

0, Rf0,

Lf0, Lb

0, Rb0, b

0, Wf0, and Wb

0 are specific to the model edge profile and appear in the Tree of Edge Profile Segments and Parameters in Appendix 1. 7.1.5.1 front bevel angle of model edge segments (f

0) ― the angle between the front surface line and front bevel line of model edge profile.

7.1.5.2 front shoulder radius of model edge segments (Rf0) — the radius of front shoulder circular arc of model edge

profile.

7.1.5.3 front and back apex length of model edge segments (Lf0 and Lf

0) — the length of apex of model edge profile, usually divided into two lengths, front apex length and back apex length, that are from origin to Cf0 or Cb0.

NOTE 3: These apex lengths can be zero for some profiles.

7.1.5.4 back shoulder radius of model edge segments (Rb0) — the radius of back shoulder circular arc of model edge

profile.

7.1.5.5 back bevel angle of model edge segments (b0) ―the angle between the back surface line and back bevel line

of model edge profile.

7.1.5.6 front edge width of model edge segments (Wf0) — the distance in the q-direction from the z-axis to the

inward end of the front bevel line at Af0 of model edge profile. There is not a segment corresponding to the edge width. W0

f is not a parameter of a single segment but is related to other parameters by the following equation.






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(1)

7.1.5.7 back edge width of model edge segments (Wb0) — the distance in the q-direction from the z-axis to the

inward end of the back bevel line at Ab0 of model edge profile. There is not a segment corresponding to the edge width. W0

b is not a parameter of a single segment but is related to other parameters by the following equation.

(2)

7.1.6 Constraint of model edge parameters by the wafer thickness

7.1.6.1 Adjusting the model edge parameters to the wafer thickness

7.1.6.2 Because the dimensions of the various regions of the model edge profile in the vertical direction must add up to the nominal thickness of the wafer, the vertical distance between points Af 0 and Ab0 must be consistent with wafer thickness t.

Any single parameter or any combination of parameters can be used as the fitting parameter to adjust the vertical distance between Af0 and Ab0 to t.

Parameters must satisfy the following equation

(3)

This equation is applied to both of front and back parameters. The, superscript f or b is omitted. Detail of the thickness adjustment is in Appendix 2.

NOTE 4: Six segments (parameters) are front bevel, front shoulder, front apex, back apex, back shoulder and back bevel. Front edge width and back edge width are additional parameters. Mathematical parameters to describe six segments are 26, as in Related Information 1, but it reduces to 8 by geometrical correlation and thickness constrain.

7.1.7 Construction of model edge profile using model edge segments and their parameters

7.1.7.1 Use the model edge coordinate system

7.1.7.2 Use the parameter adjusted to the wafer thickness. Then, construction sequence does not matter. Following is an example of constructing model edge profile using model edge segments and their parameters.

Figure 4Construction of specified model edge profile using model edge segments. In this figure, parameters are

assumed to use those in the specification table.






Spec

ified

fr

onta

pex

leng

th L

f0

½N

omin

al th

ickn

ess

specified front edge width Wf0

Specified front bevel angle f

0

Specified front shoulder

radius Rf 0

Af0

Cf0

Bf0

Front bevel

Fron

t sho

ulder

Fron

t ap

ex

O

Spec

ified

fr

onta

pex

leng

th L

f0

½N

omin

al th

ickn

ess

specified front edge width Wf0


0


radius Rf 0

Af0

Cf0

Bf0

Front bevel

Fron

t sho

ulder

Fron

t ap

ex

O

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Informational (Blue) Ballot1000A7.1.7.3 Starting front bevel line through point Af0 defined by Wf

0 using f0. Then front shoulder circle of radius Rf

0 is tangent to z-axis and front bevel line. Front bevel is Af0 to tangent point Bf0 and front apex is tangent point Cf0 to origin. It should be equal to expected Lf

0.

7.1.7.4 Model edge segments and template are mathematically constructed using equations of bevel, shoulder and apex. Details are in Related Information 1.

7.1.8 Template

7.1.8.1 Template is an area for the acceptable deviation from the specified model edge profile like SEMI M1 Edge Profile Template. The tolerance is the acceptable distance from the segments that are straight apex, circular shoulder and straight bevel, of the specified model edge profile in a direction perpendicular to them. Therefore, edge width that does not have corresponding single segment is not directly related to the template.

7.1.8.2 The outer and inner limits of the specified model edge profile are determined by adding (outward) or subtracting (inward), respectively, the distance in a direction perpendicular to the segments of the specified model edge profile to form a template within which the measured edge profile is require to fall in(see Figure 5).

NOTE 1: This procedure by CAD is offset or other similar manipulation of the specified model edge profile outward or inward by.

Nominal thickness

Tolerance

q

z

Outer line ofTemplate

Inner line ofTemplate

Thickness tolerance

Fron

tAp

exFro

nt Sho

ulder

Front Bevel

Specified Model Edge

Profile

Nominal thickness

Tolerance

q

z

Outer line ofTemplate

Inner line ofTemplate

Thickness tolerance

Fron

tAp

exFro

nt Sho

ulder

Front Bevel

Specified Model Edge

Profile

Figure 5Example of Template. Template area is defined by offsetting segments of the specified model edge profile line

by tolerance inward to inner line of template and outward to outer line of template.

7.1.8.3 When wafer thickness variation is considered, template around the starting point of bevel line is complicated as shown in the Figure 4. The thickness tolerance of Type 1.9 and 1.10 wafers as given in Table 9 of SEMI M1 is 20 m. Because the surface lines are at half thickness above and below the reference line, 10 m is applied on each surface. When all possible wafer thickness is taken into account, then, the template extends to the thickest wafer case.

NOTE 1: By single step edge shaping, thickness difference results in the edge width difference. By two step edge shaping, thickness difference results in the apex length difference.






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Figure 6 Template extends up to tmax of thick wafer case. Template end is at tnominal that corresponds to the nominal wafer case. In thin wafer case, it is down to tmin. When taking all cases into consideration that is 10m

thickness tolerance, template needs to extend up to the thick wafer case, tmax .

8 Specifying model edge profile using model edge segments, parameters, template and individual parameter tolerance8.1 To specify the model edge profile, use is made of values of the following parameters: f

0, Rf0, Lf

0, Lb0, Rb

0, b0,

Wf0, and Wb

0 that satisfy wafer thickness constrain, as mentioned in 7.1.6.1. These eight parameters define a unique specified model edge profile. Since any specification needs to accommodate scattering of actual data, additional tolerance tables provides two ways to express acceptable deviation from the specified model edge profile. One is template and the other is individual parameter tolerance. Template is an acceptable area around the specified model edge profile. Its construction is described in the previous section. Individual parameter tolerance is applied to each individual parameter as a measure of an acceptable parameter range. Examples of specifications for type A, type B, and type C profiles together with the appropriate template are given in Related Information 2.

8.1.1 Specification table

8.1.1.1 For specifying the model edge profile, table 1 lists parameters with symbol and unit. Segments and surface are additional properties related to the parameters to define them uniquely. The symbols of parameter are also useful to identify them unambiguously. Specification column is just to fill the specification numeric. For tolerance, two tables are provided. One is template and the other is list of tolerance of individual parameters to be used as a measure of acceptable scattering of the parameter.

8.1.1.1.1 Parameters of specified profile

8.1.1.1.1.1 Table 1 (a) is a specification table by filling numeric in the specification column. It lists parameters with symbol and unit. Segments and surface are additional properties related to the parameters to define them uniquely. The symbols of parameter are also useful to identify them unambiguously. Specification column is just to fill the specification numeric.

8.1.1.1.1.2 Specification column of this table is provided just to fill in the specification numeric of the parameters of the model edge segments. Parameters are listed with its symbol and unit in addition to related segment and surface. Superscript 0 is for segments and their parameters of the model edge profile.






10m10m

Nominal Thickness 20m

Tolerance

Thick wafer

Nominal wafer

Thin wafer

Nominal edge width

Outer tolerance

Target profileInner tolerance

tmax

tnominal

tmin

10m10m10m10m

Nominal Thickness 20m

Tolerance

Thick wafer

Nominal wafer

Thin wafer

Nominal edge width

Outer tolerance

Target profileInner tolerance

tmax

tnominal

tmin

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8.1.1.1.2 Tolerance

8.1.1.1.2.1 Two tables are provided for the tolerance specification. For tolerance, two tables are provided. One is template and the other is list of tolerance of individual parameters to be used as a measure of acceptable scattering of the parameter.

8.1.1.1.2.1.1 Template

8.1.1.1.2.1.1.1 Template as a tolerance is an acceptable area around the segment of the model edge profile.

8.1.1.1.2.1.1.2 Template is around the segments to accept any scattering of the edge profile.

8.1.1.1.2.1.2 Individual parameter tolerance

8.1.1.1.2.1.2.1 Tolerance of some individual parameter, if it is needed, is a measure of acceptable range of the individual parameter.

8.1.1.1.2.1.2.2 Tolerance of the individual parameters is specified when the tolerances for some parameters are needed separately as a measure of their acceptable range. For example, Wf

0 is a measure of acceptable edge width range.

8.1.2 Examples of the use of the tolerance

8.1.2.1 Use of individual parameter tolerance will obviously be used to check the measured individual parameter that is within the specified tolerance.






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Informational (Blue) Ballot1000A8.1.2.2 Other than specifying the edge profile with tolerance, the template will be used to check the measured profile. Procedure will be a separate document. Examples are as follows.

8.1.2.2.1 Example 1. Overlay the measured profile on the template. Check the measured profile is within the tolerance or not. See how close the measured profile is to the specified model edge profile.

8.1.2.2.2 Example 2. Calculate the distances from each point of the measured profile to the specified model edge profile. Compare them to the tolerance whether they are within the template. Statistics of this distance can be used to determine how close the measured profile is to the specified model edge profile.






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APPENDIX 1 EDGE PROFILE ARCHITECTURENOTICE: The material in this appendix is an official part of SEMI (doc#) and was approved by full letter ballot procedures on (date of approval).

A1-1 IntroductionA1-1.1 Edge profile is an important and complex property of wafer. The edge profile segments, in general, have shapes that are not simple straight line or circle. On the other hand, straight line and circular arc are simple for any discussions and good enough for specifying the edge profile. Test method to extract the segment’s parameters from measured data uses a test method specific algorism. To specify or to measure the edge profile, it will be more understandable if the terminology has a hierarchical structure.

A1-2 Edge ProfileA1-2.1 As schematically illustrated in figure A1-1, edge profile consists of six segments that are front/back bevel, front/back shoulder and front/back apex. Shoulder, bevel and apex are called edge altogether. These segments are, in general, non-straight or non-circular. Numerical values of segments are parameters. Local coordinate system of the edge is q-axis toward wafer center and z-axis is wafer thickness direction.

Bevel

Ape

x

Edge

q

z

Fron

tB

ack

Bevel

Ape

x

Edge

q

z

Bevel

Ape

x

Edge

q

z

Fron

tB

ack

Figure A1- 1Schematic view of wafer with enlargement of near edge region to the left showing the edge profile segment:

bevel, shoulder, and apex. Shoulder, bevel and apex are called edge altogether.

A1-3 Edge Profile Terminology ArchitectureA1-3.1 The terminology of various edge profiles should be arranged for easy and unambiguous understanding. Terminology architecture as shown in Figure A1-2 is introduced. General terminology is a higher-level one. Model edge profile and test method specific exact definitions are lower level one. Terms that are used only in a lower level standard are not included in the general terminology. Lower level exact definitions are local and apply only to those particular standards. Especially, exact definitions of the segments and its parameters are key points to the make the lower level parameters clearly understood.

A1-3.2 General terminology, as a higher-level terminology covers all edge related terms including all of non-linear and non-circular edge segments. In this sense, the general terminology is not influenced by test method. When a new restriction is imposed on a particular term like edge segment, exact definition will be necessary to reflect it. M odel edge profile segments are restricted to linear apex, linear bevel and circular shoulder that are independent of the measurement. The exact definitions specific to the model edge segments should be defined locally in the model edge profile section in this standard. Test methods need another exact definitions specific to them to make segment’s parameter extraction clearly understandable and distinguishing test method 1 as being different from test method 2. These exact definitions are local and can be applied only in its related section of test method standard.

A1-3.3 Here is an example of the exact definitions application. Bevel angle is, in general terminology, an angle between bevel and median plane but its parameter (numerical value) needs to consider a particular measurement method since numerical value of the bevel angle depends on the algorism used to extract it from the measured data. Bevel angle measured by the test method 1 is different from that of test method 2 due to the algorism difference. Reconstructed profile consists of straight and circular segments similar to the model edge profile. However, numerical values of their lengths and angles depend on the algorism used to extract them from the measured profile. Therefore, reconstructed profile is test method specific.






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8.2

General terminologyincluding all situations not to constrain exact definition of segment and its parameter

Exact definition of segment and its parameter of

model edge

Exact definition of segment and its parameter of test method 1


Test method specificModel edge



model edge






model edge






model edge




Figure A1- 2Edge profile terminology architecture. General terminology is an inclusive one. Exact definition of segment

and its parameter is local and specific to model edge profile, test method 1 and test method 2 within the general terminology coverage,

A1-4 Tree of edge profile and segmentsA1-4.1 Parameter is a numeric value of the segment schematically shown in Figure A1-3. There is not a single segment corresponding to the edge width, accordingly, edge width is not a parameter of a segment but it has a numerical value as defined in 7.1.5.5 and 7.1.5.6. Then, it can be included as a kind of parameter here. Parameters defined exactly in model edge profile, test method 1 and test method 2 have their unique symbol to distinguish each others. It is for reporting data or specifying the model edge profile unambiguously. All parameters and their correlations are illustrated as a tree of edge segments and parameters in Fig. A1-4. It branches with attached unique symbols that identify the exact definition of segment and its parameter. Edge width is not a parameter of segment but it is used in the specification (unit is m). So, it is included in this tree. Reconstructed profile consisted by using f

1, Rf1, Lf

1, Lb1, Rb

1 and b1 is not included.






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Front Bevel Angle

Back Bevel Angle

Front Bevel

Back Bevel

Fron

t Sho

ulder

Back Shoulder

Fron

t A

pex

Leng

thB

ack

Ape

x Le

ngthA

pex

Front Edge Width

Back Edge Width

q-Axis

z-Axis

Front Shoulder Radius

Back Shoulder Radius

f0

b0

Wf0

Wb0

Rf 0

R b0

L f0

L b0

Fron

t A

pex

Bac

kA

pex

(Front Surface)

(Back Surface)

Front Bevel Angle

Back Bevel Angle

Front Bevel

Back Bevel

Fron

t Sho

ulder

Back Shoulder

Fron

t A

pex

Leng

thB

ack

Ape

x Le

ngthA

pex

Front Edge Width

Back Edge Width

q-Axis

z-Axis

Front Shoulder Radius

Back Shoulder Radius

f0

b0

Wf0

Wb0

Rf 0

R b0

L f0

L b0

Fron

t A

pex

Bac

kA

pex

(Front Surface)

(Back Surface)

Figure A1- 3Constituents of Tree of Edge Segments and Parameters. Parameters that are numeric value of the segments

that are illustrated here except apex angle. Bevel, shoulder and apex are segments. Bevel angle, shoulder radius and apex length are parameters. Edge width is not a parameter of a segment but has a similar distance property. Both of segments and parameters have front and back ones. Symbol’s subscript, f or b, means front

or back and superscript 0 is for model edge parameters. If superscript is 1 or 2, it is for test method 1 or 2. When f or b is omitted, it does not concern the surface, that is, parameters can apply to both of the surfaces.

When 0, 1 or 2 is omitted, it does not care about model edge parameters or parameters extracted by test methods. Denoting of f, b and 0, 1, 2 by subscript or superscript is arbitrary.






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Figure A1 - 4 All of the edge profile segments are included here with its unique symbol. These tree first branches to front or

back part of the wafer. Then, it branches bevel, shoulder and apex that are segments of the edge profile. Bevel, shoulder and apex are called edge altogether as shown in Figure 1 and defined in 6. There is not a

single segment corresponding to edge. But edge is included here like a segment for convenience since edge width is defined clearly and its numeric value is frequently specified. Angle or length represents parameter

(numeric value) properties of the segments. Apex angle is an optional branch. It branches again according to the exact terminology by the model edge profile, test method 1 or test method 2. Unique symbol is attached to

all to distinguish each other. Edge width is not a segment but it is included here since it has a numeric property and is used in the edge specification.

A1-5 Short tablesA1-5.1 Tree of edge profile segments and parameters is rather large by including everything. It can be decomposed to simple short tables as specification table.






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Informational (Blue) Ballot1000ATable A1-1 Specification table for the model edge profile. Specification table (a) is to fill the specification numeric of the parameters of the model edge segments. Subscript f or b of symbol is for parameters of front or back segments. Superscript 0 means segments and their parameters are of the model edge profile. Specification table (b-1) is used for tolerance of the template. Specification table (b-2) is for the tolerance of the individual parameters when tolerances for some parameters are specified separately.






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APPENDIX 2 EDGE PROFILE PARAMETERS ADJUSTING TO WAFER THICKNESS NOTICE: The material in this appendix is an official part of SEMI (doc#) and was approved by full letter ballot procedures on (date of approval).

A2-1 IntroductionA2-1.1 Specified model edge profile is uniquely defined using parameters f

0, Rf0, Lf

0, Lb0, Rb

0, b0, Wf

0, Wb0, but a

distance between points Af and Ab along z-direction should be equal to wafer thickness t. This constrains the parameter values. The parameters discussed in this standard are not independent of each others. Any single parameter or any combination of parameters can be fitting parameter to adjust A f -Ab vertical distance to t. Followings are examples of the single parameter adjustment by calculation or drawing. Fitting is for front or back half of segment’s parameter. Then, t/2 is used since reference line separates them.

A2-2 Thickness adjusting by calculating a fitting parameterA2-2.1 Equation 3 shows how wafer thickness depends on the parameter. Other equations, A2-1 to 4 are the same equation but modified according to a dependent variable to show the calculation of fitting parameter from the other independent parameters. Table A2-1 is a list of independent parameters and the equation to calculate dependent parameter fitting to the thickness for various cases. In the following equations, symbol is used for segment’s parameter numeric value.

A2-2.1 In the z-direction, the distance from the origin to C i0 is simply Li0; the distance from Ci0 to Bi0 is Ri

0cosi0;

and the distance from Bi0 to Ai0 is {Wi0

– Ri0(1–sini

0)}tani0, where here and elsewhere in this appendix the

subscript i represents f or b, as appropriate. The sum of these three distances is simply half of the nominal wafer thickness, t/2, as discussed in previously in section 7.1.6.1 and equation 3.

A2-2.2 The apex length, ALi0, can be found from the relationships equation 3 to be as follows:

　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 (A2-1)

A2-2.3 The shoulder radius SRi0 can be calculated based on EWi0, ALi0, and BAi0with a given t:

(A2-2)

A2-2.4 The bevel angle BAi0 can be calculated based on EWi, ALi and SRi with a given t:

(A2-3)

A2-2.5 The edge width, ai, is calculated based on ALi0, 0, and SRi0 with a given t:

(A2-4)

A2-2.1 When adjusting thickness using one parameter while other parameters are kept unchanged, table is a relation of each parameter.






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Informational (Blue) Ballot1000ATable A2-1 List of equations, A2-1 to A2-4 to calculate wafer-thickness-depending parameter values. Other parameter values are from specification.

A2-3 Thickness adjusting by drawing the edge profileA2-2.6 There are four cases to draw the specified model edge profile adjusting the edge parameters to the wafer thickness. Last drawing segment adjusts Af0 vertical position to the 1/2 wafer thickness. Figures, A2-1 to A2-4, illustrate the situations.

A2-2.6.1 CASE I (apex last): Starting from bevel at Af0, then shoulder, Apex length is a parameter adjusting Af0reference line vertical distance to the 1/2 wafer thickness. If the front apex length is too long, nominal and too short, it corresponds to thicker, nominal and thinner wafer thickness respectively.

Figure A2-1 Starting bevel from point Af0 defined by the edge width Wf

0 using the bevel angle f0 to point Pf. Shoulder

center is on bisector. Its radius is Rf0 and tangent to bevel at Bf0 and apex at Cf0.

A2-2.6.2 CASE II (shoulder last): Starting from bevel line at Af0 using f0, then, point Cf0 defined by ALf0.

Shoulder center is on bisector and line parallel to the reference line through Cf0. Shoulder is tangent to the bevel. Radius Ri

0 is a distance from the intersection to Cf0 and is adjusted to the nominal wafer thickness.






Too

Long

fron

t ape

x le

ngth

A

pex

leng

th fo

rnom

inal

waf

erTo

o Sh

ort f

ront

ape

x le

ngth

½N

omin

al th

ickn

ess

Specified edge width Wf0

Ape

x le

ngth

adju

stin

g


0

Specified radius Rf 0

Bisector

Af0

Cf0

Bf0Pf

Too

Long

fron

t ape

x le

ngth

A

pex

leng

th fo

rnom

inal

waf

erTo

o Sh

ort f

ront

ape

x le

ngth

½N

omin

al th

ickn

ess


Ape

x le

ngth

adju

stin

g


0


Bisector

Af0

Cf0

Bf0Pf

Too

Long

fron

t ape

x le

ngth

A

pex

leng

th fo

rnom

inal

waf

erTo

o Sh

ort f

ront

ape

x le

ngth

½N

omin

al th

ickn

ess


Ape

x le

ngth

adju

stin

g


0


Bisector

Af0

Cf0

Bf0Pf

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Figure A2-2 Starting bevel from point Af0 defined by Wf

0 using f0, then, bisector through point Pf and perpendicular

line to Cf0 defined by Lf0. Shoulder center is an intersect of the bisector and the perpendicular line. Radius

Rf0 is from the intersect to Cf0 or to point Bf0. Shoulder arc is tangent to bevel at Bf0 and apex at Cf0.

A2-2.6.3 CASE III (bevel angle last): Starting from point Cf0 defined by Lf0, then shoulder arc using shoulder radius

Rf0. Bevel is from Af0 defined by Wf

0 to shoulder tangent at Bf0. Bevel angle i0 is adjusted angle to the nominal

wafer thickness.

Figure A2-3 Starting from point Cf0 defined by Lf

0, then shoulder using Rf0 to point Bf0. Center is at (Rf

0. Lf0). Bevel is

from Af0 defined by Wf0 to shoulder arc tangent at Bf0. Bevel angle i

0 is an adjusted angle between bevel and surface line.






½N

omin

al th

ickn

ess

Spe

cifie

d fro

nt a

pex

leng

th L

f0

Specified front edge width Wf0

Bisector

Perpendicular line

Bevel line

Pf


0

Cf0

Shoulder radius for

nominal wafer

Bf0

Af0

L f0

½N

omin

al th

ickn

ess

Spe

cifie

d fro

nt a

pex

leng

th L

f0


Bisector

Perpendicular line

Bevel line

Pf


0

Cf0

Shoulder radius for

nominal wafer

Bf0

Af0

L f0


Spe

cifie

dfro

nt a

pex

leng

th b

f Bevel angle adjusting


radius SRf0

Center of shoulder at (Rf

0 , Lf0 )

Front bevel angle Bf0

for nominal wafer

Af0

Bf0

Cf0 ½N

omin

al th

ickn

ess

L f0


Spe

cifie

dfro

nt a

pex

leng

th b

f Bevel angle adjusting


radius SRf0


0 , Lf0 )

Front bevel angle Bf0

for nominal wafer

Af0

Bf0

Cf0 ½N

omin

al th

ickn

ess

L f0

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Informational (Blue) Ballot1000AA2-2.6.4 CASE IV (edge width last) Starting from apex, then shoulder. Bevel of bevel angle f

0 is tangent to shoulder and intersects front surface line at Af0. Edge width Wf

0 is a parameter adjusting Af0reference line vertical distance to the 1/2 nominal wafer thickness t. If the front edge width is too long, nominal and too short, it corresponds to thicker, nominal and thinner wafer thickness respectively.

Figure A2-4 Starting from point Cf0 defined by Lf

0, then shoulder using Rf0. Center is at (Rf

0, Lf0). Point Bf0 is a tangent

point of bevel using f0. Bevel and surface lines intersect at point Af0. Edge width Wf

0 is a parameter adjusted Af0reference line vertical distance to the 1/2 nominal wafer thickness t.






Edge width adjusting

Nom

inal

thic

knes

s

Too short edge widthEdge width for nominal waferToo long edge width

Spe

cifie

dfro

nt a

pex

leng

th


radius Rf 0


0 , Lf0 )


0

Af0

Cf0

Bf0

½N

omin

al th

ickn

ess

L f0

Edge width adjusting

Nom

inal

thic

knes

s

Too short edge widthEdge width for nominal waferToo long edge width

Spe

cifie

dfro

nt a

pex

leng

th


radius Rf 0


0 , Lf0 )


0

Af0

Cf0

Bf0

½N

omin

al th

ickn

ess

L f0

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RELATED INFORMATION 1 MODEL EDGE PROFILE CALCULUSNOTICE: This related information is not an official part of SEMI [insert designation, without publication date (month-year) code] and was derived from discussions of the working group that developed the standard. This related information was approved for publication by full letter ballot on [insert date of approval]

R1-1 Mathematical modelR1-1.1 There are many ways to draw the model edge segments. One will be CAD but strict mathematical model will also be another useful method to draw the edge profile since model edge segments are straight lines and circular arcs. Figure R1-1 is a mathematical model discussed in this section. Parameter symbol used here is numeric.



Front Bevel

Back Bevel

L ｆ０

L ｂ０

Fron

t A

pex

Leng

th

Bac

k A

pex

Leng

thApe

x

Front Edge Width Wｆ０

Back Edge Width Wｂ０

q-Axis

z-Axis

Thic

knes

s t

Front Shoulder

Radius Rｆ０

Back S

hould

er

Radius

R ｂ０

Reference Line

Front Surface Line

Back Surface Line

A f0

B f0

C f0

Cb0

Bb0 Ab0

O

Fron

t Sho

ulder

Back Shoulder

Rf0

Rb0



Front Bevel

Back Bevel

L ｆ０

L ｂ０

Fron

t A

pex

Leng

th

Bac

k A

pex

Leng

thApe

x

Front Edge Width Wｆ０

Back Edge Width Wｂ０

q-Axis

z-Axis

Thic

knes

s t

Front Shoulder

Radius Rｆ０

Back S

hould

er

Radius

R ｂ０

Reference Line

Front Surface Line

Back Surface Line

A f0

B f0

C f0

Cb0

Bb0 Ab0

O

Fron

t Sho

ulder

Back Shoulder

Rf0

Rb0

Figure R1-1. A mathematical model to calculate the model edge segments. Segments, their parameters and reference points are same to Figure 1. Center of shoulder, Rf0 and Rb0 are additional points for the mathematical

model.

R1-2 Edge segments of mathematical modelR1-1.2 Mathematical model consists of straight lines and circular arcs and can be expressed by corresponding equations. Equations of apex, shoulder and bevel lines are R1-1, 2 and 3. They can express asymmetric edge profile. Suffices i is for f(front) or b(back) of symbol suffices and is applied to front or back respectively.






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Informational (Blue) Ballot1000ATable R1-1 Coordinates of segments reference points of the mathematical model of Fig. R1-1.

R1-1.2.1 Apex line:

(R1-1)

R1-1.2.2 Front and back shoulder line 　　　　

(R1-2)

R1-1.2.3 Front and back apex line

　　　　　

(R1-3)

R1-3 Tolerance and templateR1-1.3 Mathematical model of the model edge profile with tolerance that is a template needs new set of reference points corresponding to outer and inner lines of the template. The outer and inner lines created by adding or subtracting the distance properly to/from the model edge profile reference points’ coordinates. Coordinates of the new reference points are listed in Table R1-2. The model edge profile equations, R1-1 to R1-3, are modified by new parameters for template outer and inner lines. Equations of the template outer and inner lines are R1-4 to R1-9. Wafer thickness tolerance 2t is taken into account. Distance from reference line to wafer surface, t/2, increases by t.






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Tolerance

Target Edge Profile

Af0outer Af0inner

Bf0outer

Bf0inner

Cf0outer Cf0inner

Cb0innerCb0outer

Bb0outer

Bb0inner

Ab0outer Ab0inner

Outer line of template

Inner line of templateOinnerOouter

Tolerance

Target Edge Profile

Af0outer Af0inner

Bf0outer

Bf0inner

Cf0outer Cf0inner

Cb0innerCb0outer

Bb0outer

Bb0inner

Ab0outer Ab0inner

Outer line of template

Inner line of templateOinnerOouter

Figure R1-2 Template of the specified model edge profile. Outer line and inner line are offset by from the specified model edge profile same as Figure 3. New reference points on the outer and inner lines are for equations

of these lines.

Table R1-2 Coordinates of reference points of template outer and inner lines






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Template outer line

R1-1.3.1 Outer apex line: 　

(R1-4)

R1-1.3.2 Outer front and back shoulder line

(R1-5)

R1-1.3.3 Outer front and back bevel line

(R1-6)

Template inner lineR1-1.3.4 Inner apex line:






(R1-6)

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(R1-7)

R1-1.3.5 Inner front and back shoulder line

(R1-8)

R1-1.3.6 Inner front and back bevel line 　

(R1-9)






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RELATED INFORMATION 2 EXAMPLES OF SPECIFICATION TEMPLATESNOTICE: This related information is not an official part of SEMI [insert designation, without publication date (month-year) code] and was derived from discussions of the working group that developed the standard. This related information was approved for publication by full letter ballot on [insert date of approval]

R2-1 IntroductionR2-1.1 Examples of specified model edge profiles described by the model edge profile segments and specification parameters in this guide are shown. For these examples, the parameters were selected from the edge profiles measured in a pilot study carried out by the SEMI Edge Profile Working Group, within the SEMI International Advanced Wafer Geometry Task Force of the Global Silicon Wafer Committee.

R2-1.1 In this study, three representative edge profile types: type A, type B and type C were measured by a three different organizations, using different commercially available edge profile measuring systems. The segments of the edge profile model used in each case were approximately the averages of the parameters reported by the three organizations on a typical wafer of each type. The graphs show the specified model edge profile (solid curve) and the two limits (dashed curves) that define the allowable region of the templates. The graphs also show in light weight dashed curves the much looser T/3 and T/4 edge profile templates in SEMI M1.

R2-2 Type AR2-2.1 The example specification for the type A edge profile is given in Table R2-1 and the graph of the template is given in Figure R2-1. For this symmetrical example, the values of ALi0 calculated is 104.44 m using following equation that is same to 6.6-1 equation.

(R2-1)

R2-2 Type BR2-3.1 The example specification for the type B edge profile is given in Table R2-2 and the graph of the template is given in Figure R2-2. For this symmetrical example, the values of bi calculated is 168.45 m






TargetInner RangeOuter RangeT/3T/4

Figure R2-1Example of Type A Edge Profile Template

Specified ProfileInner RangeOuter RangeT/3T/4


LETT

ER (Y

ELLO

W) B

ALL

OT


R2-3 Type CR2-4.1 The example specification for the type C edge profile is given in Table R2-3 and the graph of the template is given in Figure R2-3. For this symmetrical example, the values of bi calculated is 69.32 m.







Figure R2-2Example of Type B Edge Profile Template




LETT

ER (Y

ELLO

W) B

ALL

OT


NOTICE: SEMI makes no warranties or representations as to the suitability of the standards set forth herein for any particular application. The determination of the suitability of the standard is solely the responsibility of the user. Users are cautioned to refer to manufacturer's instructions, product labels, product data sheets, and other relevant literature, respecting any materials or equipment mentioned herein. These standards are subject to change without notice.

By publication of this standard, Semiconductor Equipment and Materials International (SEMI) takes no position respecting the validity of any patent rights or copyrights asserted in connection with any items mentioned in this standard. Users of this standard are expressly advised that determination of any such patent rights or copyrights, and the risk of infringement of such rights are entirely their own responsibility.






Figure R2-3Example of Type C Edge Profile

Template

