Utmost TFT Training Part1

7/25/2019 Utmost TFT Training Part1

http://slidepdf.com/reader/full/utmost-tft-training-part1 1/96

- 2 -UTMOST

What is UTMOST?

UTMOST III SPICE Modeling Software generates the most

accurate, high quality SPICE models for analog, digital,

mixed-signal, and RF applications

Leading IDMs, foundries, and fabless companies use

UTMOST III to perform data acquisition, devicecharacterization, parameter extraction, and model

verification



- 3 -UTMOST

Agenda

Why need modeling

Utmost installation

Utmost simple Tutorial

Utmost menu and option detail introduction

TFT model introduction



- 4 -UTMOST

Why need modeling

Model card is the bridge between foundry and fabless

Circuit accuracy depends on accuracy model

Wrong/inaccuracy model leads to low yield or zero yield

Model card can monitor the process variation.

Use model card can speed up the time to market or profit



- 5 -UTMOST

UTMOST Inputs and Outputs



- 6 -UTMOST

Utmost Installation

Install the Utmost package

Download the binary packaging

Mkdir ../target path/Silvaco

Cd ../target path/Silvaco

Gunzip < /cdrom/utmost.tar.gz.|tar xf -

Install the SFLM

Download the binary sflm.tar.gz

Mkdir /opt/simucad

Cd /opt/simucad

Gunzip < /cdrom/sflm.tar.gz.|tar xf –

/<install dir>/bin/sflm –install

Bring up web browser http://losthost :3162

Register by online or offline to get the ossid

Apply the license by the ossid and install it





- 8 -UTMOST

Simple Tutorial :Utmost main screen& select model

Click utmost button and select interactive item

Select TFT model



- 9 -UTMOST

Simple Tutorial: open the file manager

Click the File button in the Utmost main screen

Click the File Manager



- 1 0 -UTMOST

Get the file screen

Drag the setup file to the setup mailbox, the box will show

message loaded

Quit the page

Simple Tutorial: load the setup file



- 1 1 -UTMOST

Simple Tutorial :Open the System main screen

Click the system button on the utmost main screen



- 1 2 -UTMOST

Simple Tutorial: Setup the system options

Click the button on the system screen to setup the options

Set the get RAW data option to simulation or measurement.

Set the graphics control to manual Set the spice model to internal model or smartlib

Set temperature modeling to Disabled

Set the probe control to manual

Set continuity test to Disabled. Keep others option or parameters as usual



- 1 3 -UTMOST

Simple Tutorial: Open spice model screen

Click the Utmost main screen->File->spice model button

Select the spice simulator

Select the model name Click the load model button

Quit the screen



- 1 4 -UTMOST

Simple Tutorial: Open the output log file screen

Click the File->output log files in the utmost main screen

Enter log file name

Enter the header info

Click the Open new

All the data will be in log file



- 1 5 -UTMOST

Simple Tutorial: Open the setup and result screen

Click the Setup button in the utmost main screen



- 1 6 -UTMOST


Change the Analysis Filter to DC

Select IDS/VDS button

Click the routine control in the utmost main screen



- 1 7 -UTMOST


Set the Meas. Sections field to 5.

This value controls the number of sweeps performed in thesimulation.

Close the Routine Control Screen by clicking on the Quit

button.



- 1 8 -UTMOST

Simple Tutorial: open model Strategy in utmost screen

Click Strategy button to open the Model Strategy screen

Ensure the device is actived



- 1 9 -UTMOST

Simple Tutorial: Open the extraction screen

click the Extraction button to Open the extraction screen

on the main UTMOST screen.

Select the ID/VD-VG routine

Click on the Measure button.



- 2 0 -UTMOST

Simple Tutorial: Open the graphic screen

Click on the Measure button.

UTMOST will simulate the ID/VD-VG curves according to

the measurement setup and display the results in a

graphics screen.



- 2 1 -UTMOST

Simple Tutorial : Fit and Simulation

There are many options available within the graphics screen.

Under the Options button, select Fit. This invokes the

UTMOST fit algorithm for the ID/VD-VG routine.

Option-> simulation, simulate the curves by model parameters

To quit the graphics screen, click on the Return button.



- 2 2 -UTMOST

Simple Tutorial: open DC measurement screen

To re-simulate the same data using a modified

measurement setup,

locate the Setup and Results screen

click on the Set Measurement button.

opens the DC Measurement Screen.



- 2 3 -UTMOST

Simple Tutorial : Change measurement condition

To alter the voltage sweeping parameters simply edit the

fields adjacent to the corresponding parameter names.

ID/VDS@VGS point 51

Fill in the vds_start_vd

vds_stop_vd

vgs_start_vd

vgs_step_vd

ID/VGS@VDS point 51

Fill in the vgs_start_vg

vgs_stop_vg

vds_start_vg vds_step_vg

Leave the DC Measurement Screen open

Press Measure on the Extraction screen.



- 2 4 -UTMOST

Simple Tutorial: close and save

To close the log file, open the Output Log File screen and

click on Close File.

To save the UTMOST setup, open the File Manager screenand click on the Setup & Log checkbox .

Enter a new name in the Setup File Name field and click on

the Store button.

The File Manager should also show the log file just created.

If no icon for this log file appears in the files area, place the

pointer in the Directory text field and press Return. This will

update the files area.



- 2 5 -UTMOST

Detail introduction: File manager

Filtering

Editing

doulbe click file

Don’t edit binary

Naming

.s for SPICE files

.l for SPICElibrary files

.c for SPICE files

used in circuits

Printing file

Deleting file

Save file

Click Setup&log



- 2 6 -UTMOST

Detail introduction: Primary files

The File Manager is used to initialize UTMOST.

Setup files store system and program operation

information, including ex, meas, opti etc….

Log files are used to store measurement data and

measurement biasing information in ASCII format.

List files contain the results of UTMOST parameter

extractions, including some primitive statistical

analysis results, such as the maximum, minimum,and average values of the model parameters

extracted during the measurement session.

SPICE models are stored in SPICE library files.

SPAYN is a statistical analysis program designed toidentify and help resolve production deficiencies

and to increase yield

Spice model select the model level type

Reedholm file and Keithley file allows utmost to

read or convert Reedholm/Keithley datarespectively



- 2 7 -UTMOST

Detail introduction: List file

Fill the file name in the field

Click open new to create file

Click overwrite to replace file

Click copy to save selected parameters to listfile

Click store to save current entered parametersto list file

Click CLOSE FILE to close file

Parameters can be added by Utmost->Parameters->attributes

List has four typeS

List1: Max, Min, Mean, StandardDeviation of selected parameters, and asummary of die names used andassociated parameter values.

List2: Max, Min, Mean, StandardDeviation of selected parameters, and a

summary of all parameter values.

List3: A simple summary of selectedparameters.

List4: A summary of results, tagged with

wafer and die identifiers.



- 2 8 -UTMOST

Detail introduction: Hardware setup (IV/AC/CV/Noise)

Utmost->Hardware->Configuration Select instrument type Click CPU side

GPIB serial port

Port setup Baud rate Port name (default by computer) Check communication by

POLLING button

Set SMU and GPIB port No.

Set Continuity test( check theconnection quality)

Set Calibration Device connect to GND Test the cable and wire R

Instr Setup to set external

power supplier to IV meter Stimulate mode

Pulse1/Pulse2 options enable1/2 sources to be used.

User option selects useroperation mode.

System option selects normaloperation mode.



- 2 9 -UTMOST

Detail introduction: Hardware setup

Utmost->Hardware->Probing•Select prober type

•Select interface type

•Fill in prober address•Set the prober delay (100+sec)

•#Wafers defined the wafer

number in the cassette

•Select units by English or metric

•Stop option valid in some station.To load new wafer after stop

•Skip unused wafer: skip wafer in

wafer cassette

•Polling to check the prober

connection with computer

•Load/unload/move/set home/go

home/contact/no contact controls

the probe card automatically.



- 3 0 -UTMOST

Detail introduction: Hardware Setup

Utmost->Hardware->instrument

•usually high accuracy or high

power instruments must be

manually controlled.

•Select the

instrument

function

I/V meter, I/V source•Select the instrument type

•Check the connection by Polling

•Quit



- 3 1 -UTMOST

Detail introduction: System screen configuration

Utmost->system



- 3 2 -UTMOST

Detail introduction: System option

Edit names and Values

If Disabled, then parameter and routine names are read-only

If Enabled, then parameter and routine names may be edited.

Get Raw Data From

To define the data source to be used by Measurement, Simulation, Log

File, Reedholm, Keithley and Drawing.

Measurement, data is taken from instruments connected to UTMOST.

Simulation, uses the currently defined model to simulate a device.

This option can be used to compare a developed model with a real device.

Selecting Log File makes it possible to read data from a log file created in

UTMOST.

Selecting Reedholm allows UTMOST to read data from a Reedholmformatted file.

Keithley, UTMOST can be used to read data from a Keithley formatted

file.

The Drawing option will be available in future versions of UTMOST.



- 3 3 -UTMOST

Detail introduction: System option

Prober Control :Three options: Manual, SemiAuto and Auto.

System Messages:

Enable :need operator intervention when individual measurement Disabled :all under computer controll when measurement

Spice Models: determines how UTMOST performs a simulation.

set to External SPICE, UTMOST use an external SPICE program for

simulations. set to Internal Models, UTMOST uses its own internal simulator

set to interpreter, model implemented by smartspice interpreter, to

use external spice to simulate result

Set to Smartlib, would use a separate internal rubberband simulatoronly for DC characterics.



- 3 4 -UTMOST

Detail introduction: system screen configuration

Group Extraction disabled, selected model parameters are logged to SPAYN or list files for

each device chosen.

enabled, the model parameters are logged only once, after all chosen

devices have been tested and analyzed. Technology:

to set according to the UTMOST technology currently in use, such TFT orMOSFET

Graphics Control Set to Manual, UTMOST displays a plot and wait for the Return button to

be pressed before continuing.

Set to No Graph, UTMOST does not display graphs.

Set to Pause, UTMOST will wait a time before display the nextmeasurement.

The waiting time can be set by entering a value in the Pause Wait Timetext field.

MACRO Modeling Set to Enabled, UTMOST uses the netlist and models provided in the

VYPER control file. Set to Disabled, UTMOST uses its internal netlist to simulate.



- 3 5 -UTMOST

Detail introduction: system option

Continuity Test set to Enabled, a continuity test as defined in an SMU Continuity Test screen is performed on each test site.

Set to Disabled, will not do the continuity test on each test site

Repeated Measurement Enabled to ensure all the device can be correctly measured

Disabled will skip the device which has the temporary files (stored data) existed. Temperature Modeling

Enabled, UTMOST to drive connected computer-controlled temperature ovens

Disabled, UTMOST assumes that all measurements are performed at room (nominal)

gds/gm Model It controls how the gds/gm data is produced.

If set to Computed, UTMOST calculates the gds/gm data from the Ids data measured.

There are four different methods:Lagrange 5-point and 3-point methods, and the Linear 5-point and 3-point

methods # of Terminals: describe the device terminal

.Opt Method : Users can switch between the Levenberg-Marquart and the Downhill Simplex method

Nominal Temperature: Nominal Temperature default is room temperature.

File Autoclose Time: This feature avoid measurement data lost by failure to close the files manually.

Usually used in multiple device or several wafer in probe mode measurement

DC Long Delay: defines a delay between measurements if the device needs time to cool etc.

AC Read Delay: defines a delay between the reading the measured AC points from the output buffer of the network analyzer.

AC Sweep Delay: Defines the delay necessary to measure all AC points for each s-parameter family



- 3 6 -UTMOST


System Init: initialize the setup enviroment.

Print Results: stores the extracted parameters to an ASCII file.

The file is stored in the current directory and has a name in the formatPRINTxx, where xx is a sequential number starting at 00.

The file can be print in file manager

Title Block (die information) displays the Title Block screen,

This screen allows process attributes to be set. These attributes arestored in log files and act as labels in plots

The Title Block screen will also open automatically when List Files orSPAYN Interface are selected from the Files menu.

dcgmin, reltol, vnto, abstol, numdgt, and dnumdgt

above options are SPICE parameters, used for external SPICE and SmartLib simulation.

Replot displays the Replot screen. This screen allows previously simulated or

measured plots to be displayed. To view a plot, select the relevant line of

the plot list and click on the Apply button.



- 3 7 -UTMOST


Raw data

Display the Raw data set screen

Data manually modified and click the apply to the graphics

In Graphics, use control->show XY option, data can be viewed byreopen the raw data.

Run time debug

Check and debug the interaction of utmost with instrument

Check and debug the interaction of utmost with external spice



- 3 8 -UTMOST

Detail introduction: Local Optimization

Utmost->Local Opti.

•Used to construct the required local optimization strategies

•Yellow diamond indicates that the corresponding step has not been acti

•Red diamond indicates that the corresponding step is in progress.

•Green diamond indicates that the corresponding step has been success

•Blue parameters can not be recognized in current model•Red Parameters indicates values reached their upper or lower boundar



- 3 9 -UTMOST

Detail introduction: Local optimization

Click the Define strategy

•can use current/current derivative/ current+derivative as local optimization target

•Enter correct routine number in the routine field

•A red flag indicate the parameters actived

•Target selection: select the curves range for optimization

•Select strategy by click select strategy in local optimization screen.

•Define the print information by click the Define printout in local optimization screen



- 4 0 -UTMOST

Detail introduction: Parameters screen

Utmost->Parameters



- 4 1 -UTMOST

Detail introduction: parameters screen

To specify the parameter name, value of optimized, fit

initial ,user initial, minimum, maximum

Three mode: edit, insert, delete

Click attribute button to mark the parameters in spice file,list file and spayn file

Copy parameters among opti, fit, user, min, max

Select routine by enter the routine number field, routinename will be changed corresponding with the name

Select strategy number by selecting the parameters

After selection the total opt. button will show the parameters

number

Click the Total opt. button , it will clear the selection



- 4 2 -UTMOST

Detail introduction: Setups option

Utmost->setups



- 4 3 -UTMOST

Details introduction: setups option

Display a table of routine names for current

technology

Analysis filter can display particular analysis

type by input the analysis type or click theright arrow

Click on the Clear Last Data button to delete

any data that is related to the current routine,

including temporary files and results files.

To delete data from all routines, click on the

System Init button on the Common Control

screen.

The Create Routine and Modify Routine

buttons provide functions that are to be usedby routine developers only.

Click on the Attributes button to open the

Routine Attributes screen .This screen

provides information about the capabilities of

the selected routine.



- 4 4 -UTMOST

Detail introduction: DC measurement screen

Utmost-> setup->set measurement



- 4 5 -UTMOST

Detail introduction: DC measurement screen

# Of Setups field can be used to create multiple

measurement setups for a given routine.

To change the number of setups, enter the required

number in the text field and press the Return key.

UTMOST automatically copies the current setup toany new setup.

To select an individual setup, use the pop-up menu

next to the Setup label.

Clicking on the Fit Vars button opens the Fitting

Variables screen. This screen is used to set variablesthat control the UTMOST fitting algorithms and

parameter extraction.

Sweep mode can be linear, log10, log 25, log50

To model can choose ID/VG, Gm, ID/VD etc..

Can select GDS or RDS

Can setup the SMU range



- 4 6 -UTMOST

Detail introduction: Extraction screen

The Extraction screen is used to initiate all principal UTMOST operations,

such as measurement, parameter extraction, simulation, and optimization.

Utmost->extraction



- 4 7 -UTMOST

Detail introduction: Extraction screen

Optimization and Fitting Options UTMOST can perform fitting (parameter extraction) and optimization

automatically after measurement data is obtained.

The Fitting and Optimizer buttons on the Routine Control screen can be set

individually for every routine in the test sequence.

If the Fitting and Optimizer buttons are Disabled, fitting and optimization can

be performed from the Graphics screen

Repeated Measurement

Control

options



- 4 8 -UTMOST

Detail introduction: Configuring Routines

Utmost->Routine control

Click utmost->setup->create routine or select a routineOpen the routine control screen

Fitting, Simulation and Optimization are Enabled, three tasks are performed

in the following order: Fitting, Optimization, and Simulation.

two or more of these buttons are enabled while UTMOST is in manual mode,

the user must press the Return key to move from one process to the next



- 4 9 -UTMOST


Fitting If the Fitting button is Enabled, UTMOST automatically attempts to extract fitting

parameters from the measured data when a measurement is completed.

If a local optimization sequence is enabled for the routine in use, the regular fittingoperation is followed by the local optimization sequence.

The fitting operation is equivalent to selecting Fit from the Options menu of the Graphicsscreen. If the Fitting button is Disabled, then no automatic fitting or local optimizationtakes place.

Fit Sections The number in the Fit Sections button shows the number of subsets of measurement

data that will be fitted for the current routine.

Simulation If the Simulation button is Enabled for a routine, simulation is performed automatically

after the measurement and after fitting and local optimization,

the Simulation button is equivalent to selecting Simulation from the Options menu of theGraphics screen

Global Optimization If the Global Optim. button is Enabled for a routine, the optimizer is invoked

automatically when a measurement is completed.

Enabling the Global Optim. button is equivalent to selecting Global Optim. from theOptions menu of the Graphics screen.

If the Global Optim. button is Disabled, optimization must be done manually from theGraphics screen. The UTMOST optimizer is not available for all routines. The Routine

Attributes screen, defined as part of the Setup and Results screen, can be used to checkif optimization is allowed for a given routine.



- 5 0 -UTMOST


Local Optimization If the Local Optim. button is Enabled for a routine, then the optimizer is invoked

automatically when a measurement is completed.

Enabling the Local Optim. button is equivalent to selecting Local Optim. from theOptions menu of the Graphics screen.

If the Local Optim. button is Disabled, optimization must be done manually from theGraphics screen. The UTMOST optimizer is not available for all routines. The Routine

Attributes screen, defined as part of the Setup and Results screen, can be used to checkif optimization is allowed for a given routine.

Plotter If the Plotter button is Enabled, and PostScript is selected in the hardware configuration

screen, when a measurement is completed UTMOST automatically generates aPostScript file.

To create a PostScript file with a different name, enter the new filename in thePostScript/HPGL text field in the Routine Control screen.

Enabling the Plotter button is equivalent to clicking on the Plot button on the Graphicsscreen.

Measurement Sections The Measurement Sections text field defines the number of curves that will be measured

for the current routine. For example, when measuring IDS for different values of VDS, it iscommon to produce a family of curves by varying VGS for each set of VDS values. TheMeasurement Sections field gives the number of VGS increments.

Optimizer Setup

The Optimizer Setup button opens the Optimizer Setup/Status screen. This screen isused to assign values to variables required by the optimizer.

D il i d i C fi i R i



- 5 1 -UTMOST


Data Setup The Data Setup button opens the Data Setup screen. This screen displays each

measured data point and the value of the measured and simulated data at that point.

An error value is given to show the percentage error between simulated and measured

data.

If several devices are measured, it is possible to display the information for an individual

device by selecting the device name in the Structure Name section.

To print the information, click on the Print button. This sends the data displayed on the

screen directly to the connected printer.

To save the information to a file, enter a name in the File Name text field and click on theStore File button.

D t il i t d ti C fi i R ti



- 5 2 -UTMOST


Temperature The Temperature button opens the Temperature Setup screen.

The number of temperature points and the temperature at each point are constant for all

routines.

To mark a routine for a particular temperature, click on the button to the left of thetemperature value and a flag appears.

The temperature flags can be set and cleared by the SET ALL and CLEAR buttons.

The selected temperature points can be stored in a text file, which can be loaded to

UTMOST later.

D t il i t d ti C fi i R ti



- 5 3 -UTMOST


Multiple Select The Multiple Select button opens the Multiple Routine screen.

If a routine has several distinct stages (routine number >0), this screen allows the user to

control the stages performed by UTMOST.

Result The Result button opens the Result screen.

This screen displays which parameters are extracted by the current routine using regular

fitting techniques.

enter a number in the appropriate Extracted text field.

enter the desired values in the Minimum and Maximum text fields.

save a parameter value in a SPAYN or List file, click on the SPAYN or List button.

If a parameter is marked for saving, a flag is displayed next to the parameter name. To

unmark a parameter, click on the button again.




- 5 4 -UTMOST


Preset opens a parameter Preset screen for the current routine.

can be used to preset selected parameter values and/or limits that take effect whenever

the routine is activated or routine finished

this screen also can be used to reset selected parameter values and/or limits after the

routine is finished.

The Routine field displays the currently selected routine.

The “# of parameters” field displays the number of parameters to be set (default is zero).

The parameter names in the Names column can be edited only when the Edit button in

the System window is set to Enabled. pre-set will be transferred to the UTMOST Parameters screen when the routine is

executed.




- 5 5 -UTMOST


Local Optimization Sequence

Local optimization is possible using many UTMOST routines.

This screen defines a sequence of local optimization strategies.

These strategies are set up in the Local Optimization screen of

the main UTMOST window.

user enters the strategies into the local optimization sequence

using their numbers, as defined in the Local Optimization

environment.

Detail instruction: Modeling Strategies



- 5 6 -UTMOST


The Model Strategy screen is used to set and to display a

summary of measurement and optimization strategies for

each routine, device, group and temperature.

The following information is defined in other screens:

Routine name - Setup and Results screen.

Temperature - Temperature Setup screen (from Routine Control).

Group - Group List screen (Hardware Probing). Device Name, Polarity and Geometry - Device Pad Definition

Screen (Hardware Probing; any changes made in this screen

also changes the Device Pad Definition screen, as the two

screens work interactively).

Setup Number – Measurement Setup under Setup and Results

screen.

Optimization Set – Parameters screen




- 5 7 -UTMOST


Utmost->Strategy




- 5 8 -UTMOST


The Model Strategy screen is routine dependent.

This screen can be used to mark or activate any available device formeasurement by the routine

If temperature modeling is enabled, devices can be measured at different

temperatures If multiple groups have been defined the group number canbe changed by clicking on the Group button.

Click on the Clear Sequence button to restart selections for the currentroutine.

the Set All Grps (set this group, set all temp.) button will highlight(select) all devices in all groups.

There are six possible optimization strategies.

The Setup Number refers to a measurement setup defined in theMeasurement screen of the Setup and Result screen. Severalmeasurement setups can be defined in the Measurement screen. TheSetup # button on the Model Strategy screen can be used to set the

measurement conditions for the particular device and routine. The polarity of a device can be changed to . available polarities (for

MOSFETs the options are NMOS, PMOS, and Dummy)

The Model button is used to select which set of parameters is used toperform simulation and optimization.

Geometry (Width and Length )

Detail introduction: Displaying Results Graphically



- 5 9 -UTMOST


Utmost->extraction->measurement

A Graphics screen can display single and multiple plots.

the number of plots depends on the number and type of routines

in the measurement sequence, Up to 18 plots .




- 6 0 -UTMOST


The Attributes button on the Graphics screen opens the

Graphics Attributes screen.

•Maximum and Minimum values for the

X and Y axes

• Scale of X and Y axes, X and Y axis

labels, X and Y axis units

• Plot title

• Frame color• Line color, line style and marker type

• Continuity • Optimization (viewport)

box color and line style

• Scaling




- 6 1 -UTMOST


Options Raw Data

The Raw Data option refreshes all the plots in the graphics screen with original

measured data. All simulation, optimization, and fitting results are removed from the

Graphics screen, but remain in the Parameters screen and the Results screen. Fit

Selecting Fit invokes the UTMOST fitting algorithm for parameter extraction for the

given routine.

Simulate

The Simulate option causes UTMOST to simulate data for the current routine.

Global Optimize

The Global Optimization is invoked by selecting the Global Optim. option.

Local Optimize

The Local Optimization is invoked by selecting the Local Optim. option.

Exchange The Exchange option allows the user to swap measured and simulated data.




- 6 2 -UTMOST


Option Modeling

The feature allows the user to perform multiple simulations for the routine selected.

Spice Model Development screen allows the user to sweep model parameters and

temperature, and to perform a simulation at each step. To select a model parameter to sweep, click on the numbered button next to the

parameter name. The start, stop, and step values for the sweep should be entered

in the fields provided.

The sweep types available are Linear, Log3, Log5, Log10, Log15 and Log20.

To perform the simulations, click on the Execute button. The simulation results can

be displayed in two or three dimensions. This feature is controlled by the 2D/3DGraphic button.

For 3D display, the colors can be adjusted from the Shadowing screen. The

Shadowing screen is opened by clicking on the Shadowing button on the Spice

Model Development screen.




- 6 3 -UTMOST

p y g p y

Rubberband

With rubberbanding, individual model parameters can be

adjusted, and the results are displayed immediately.

The Save Results button writes the modified parameter values tothe optimized column of the Parameters screen.

There are five simulation speeds available.




- 6 4 -UTMOST

p y g p y

option

Calculator

The Calculator is available for performing simple calculations. In

some routines it can be programmed to modify measured data.

Emulator

The Emulator option opens the Emulator 4145 screen. This screen

emulates the function of the HP4145 instrument in its interactive

measurement mode.

Agenda for TFT modeling training



- 6 5 -UTMOST

g g g

Model selection

Model layout design and manufacturing

Model IV/CV/Timing curves measurement

Model parameters extraction

Model parameters QA

SILVACO TFT Models Selection



- 6 6 -UTMOST

Currently supports 4 TFT device models

Level=15 ( Leroux Amorphous Model ) Level=16 ( Berkeley Polysilicon Model)+Leakage current Model

Level=35 ( RPI Amorphous Model ) ( Version=1 & Version=2)

Level=36 ( RPI PolySilicon Model ) ( Version=1 & Version=2)

RPISCALE=1 SMART=0,1,2,3 Model

TFT Models



- 6 7 -UTMOST

Provides 4 models :

Leroux model (Amorphous Si, level 15)

RPI model (Amorphous Si, level 35)

Berkeley TFT model (Polysilicon, level 16)

RPI model (Polysilicon, level 36)

Source Drain

Glass substrate

Gate

Gate insulator

Passivation Intrinsic a-Si

Conducting channel

N+ a-Si N+ a-Si

GateDrain

Sourcegate oxyde

quartz or glass substrate

poly-Sin+ n+

SiO2 coating

SVA: 4PR TFT



- 6 8 -UTMOST

DRAIN

PA-SiNx

n+ a-SiSOURCE

GATE

a-Si

GLASS

ITO

G-SiNx

TFT Equivalent Circuit



- 6 9 -UTMOST




- 7 0 -UTMOST

Model selection




Model parameters QA

TFT model layout design for DC/AC measurement



- 7 1 -UTMOST




- 7 2 -UTMOST

Model selection




Model parameters QA

IV curve measurement



- 7 3 -UTMOST

IDS/VGS( Drain current)

VGS sweep over a defined range@ a set of VDS

IDS/VDS

VDS sweep over a defined range @ a set of VGS

CV Measurement



- 7 4 -UTMOST

CGDO( Gate to Drain Overlap Capacitance)

Gate to Drain Voltage sweep from big negative to big positive value. The

overlap typical value is 1200microns, capacitance typical value is 25 to

70 pf.

CGSO( Gate to Source Overlap Capacitance)

INTCAP

CGS ( Source: LCR H,DC ,Gate :LCR L, Drain/B DC)

CGD (Drain: LCR H, DC, Gate: LCR L, Source/B DC)

CGC (Drain/Source short, LCR L, Gate LCR H,B DC)

CGB (Drain/Source short DC, Gate LCR H, B: LCR L)

CGG (Drain/Source/B short, LCR L, Gate: LCR H)

Timing Domain measurement



- 7 5 -UTMOST

Drain connect to VDD

Source connect to GND of Oscilloscope

Ultmost read the period of each VDD

Display the Tpd VS VDD




- 7 6 -UTMOST

Model selection


Model IV/CV/Timing curves measurement Model parameters extraction

Model parameters QA

Device Characterization



- 7 7 -UTMOST

Saturation Region

Linear Region

-14

-12

-10

-8

-6

-4

L o g

[ D r a i n C u r r e n t ( A m p s ) ]

-30 -20 -10 0 10 20 30

Gate Voltage [Volts]

Vds = 10V

Leakage Above-Threshold

Sub-ThresholdTopmost curve: Vgs = 20 V; Step: -2.5 V

0 10 20 30

Drain-source voltage [V]

0u

2u

4u

6u

8u

10u

D r a i n c u r r e n t [ A ]

Different Regimes of Operation

Model parameter extraction



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Select model type

Loading curves Global extraction (auto)

Fine tune and optimization

Simulation

Check Error criteria

Iteration

Generate the model card

TFT model Routine



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A typical parameter extraction sequence would proceed as follows:

Use the IDS/VGS routine to measure IDS vs. VGS curves measured at various

drain-source biases.

Local or Global Optimization strategies could be implemented in order to extractthreshold voltage, mobility, drain-induced barrier lowering, subthreshold, and gate-

induced drain leakage parameters.

Use the IDS/VDS routine to measure IDS vs. VDS curves measured at various

gate-source biases.

Local or Global Optimization strategies could be implemented in order to extractvelocity saturation, channel length modulation and hot carrier parameters.

Use the CGDO and CGSO routines to extract gate-drain and gate-source overlap

capacitances and associated parameters.

Extract temperature parameters using Local or Global Optimization techniques

with IDS/VGS and IDS/BDS data measured at temperatures other than roomtemperature.

Use the ton/toff or timering routines to extract TFT time domain parameters.

TFT DC modeling routine1: IDS/VDS



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IDS/VDS (Drain Current Modeling Routine) The IDS/VDS routine is used to verify TFT functionality and to measure TFT

drain current.

This measured data can be used to simulate and optimize TFT model

parameters related to velocity saturation and channel length modulation.

Data Acquisition IDS vs. VDS@VGS (constant)

The number of VGS voltage steps is defined in the Routine Control screen

using the Measurement Sections field.

A TFT device is connected according to the SMU definitions, and the VDS

and VGS voltages defined.

Typically, TFT devices are used in the forward bias mode. When this is the

case, the VDS drain voltage is swept from 0V to the VDSmax. If the TFT

device is used in forward and reverse bias mode, then the VDS drain voltagecan be swept from -VDSmax to +VDSmax.

TFT DC modeling routine2: IDS/VGS



- 8 1 -UTMOST

IDS/VGS

The IDS/VGS routine is used to verify TFT functionality and to

measure TFT drain current.

measured data can be used to simulate and optimize TFT modelparameters related to threshold voltage, mobility, subthreshold,

drain-induced barrier lowering and gate-induced drain leakage.

Data Acquisition

IDS vs VGS @ VDS (constant)

The number of VDS voltage steps is defined in the Routine

Control screen using the Measurement Sections text field.

The TFT is connected according to SMU definitions, and the VDS

and VGS voltages are defined.

Typically the TFT will be measured from weak-inversion to

strong-inversion with the gate bias being swept from a negative

to a positive voltage in the case of an n-type TFT device.

TFT DC modeling routine3: VTO



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VTO (Threshold Voltage Extractions)

The threshold voltage extraction routine VTO measures a single

IDS/VGS curve and extracts model parameter VTO from the

largest slope of the curve.

This routine can be used for extracting temperature model

parameters if measurements are performed at a number of

different temperatures.

Data Acquisition

A data set is obtained as the drain current values for one gate

voltage sweep.

A TFT device is connected according to the SMU definitions, and

the gate voltage VGS is swept over a specified voltage range

while the drain voltage VDS is kept constant.

Threshold voltage measurement and extraction is typically

performed on a large TFT device (typically 25/25).

The model parameter VTO represents the threshold voltage

value at 0V of substrate bias and low value of drain voltage VDS.

TFT DC modeling routine4: LAMBDA



- 8 3 -UTMOST

LAMBDA (Channel Length Modulation)

The channel length modulation routine LAMBDA measures a

single IDS/VDS curve for a constant gate voltage VGS.

From this single data set, model parameter LAMBDA is extracted.

Data Acquisition

A data set is obtained as the drain IDS current values for one

drain voltage VDS sweep, while the gate voltage VGS is kept

constant.

The VGS voltage value is typically way between VTO and 0V.

The model parameter LAMBDA models the channel length

modulation effects in a TFT device. Due to this effect, a TFT

device has a finite output conductance in the saturation region.

TFT DC modeling routine5: BVDO



- 8 4 -UTMOST

BVDO (Drain to Source Breakdown Voltage Extraction) The BVDO drain to source breakdown voltage routine measures the

voltage across the drain to source terminals, while the gate terminals isshorted to ground and current is forced into the drain terminal.

The drain to source breakdown voltage occurs at the point where thevoltage across the terminals starts to increase rapidly. The breakdownvoltage parameter BVDO is extracted at a specified current I_to_fit.

Data Acquisition The forcing drain current should always be swept logarithmically across a

specified current range while the drain to source voltage is measured. The SHORT integration time option and the LOG10 logarithmic sweep

option are recommended in order to ensure minimum heat generationinside the device during the measurements.

The breakdown voltage measurements are destructive if not handled

properly. Set the current compliance properly and carefully to avoid device

destruction.

The value of BVDO is extracted at a given drain current I_to_fit. BVDOcan be extracted over temperature for process control purposes. NoSPICE parameter is extracted.

TFT DC modeling routine6: ALL_DC



- 8 5 -UTMOST

ALL_DC (Multitarget TFT DC Modeling) The ALL_DC routine is used to measure a set of IDS versus VGS and IDS

versus VDS curves for a number of TFT geometries.

These data sets can be used to extract the entire scalable set of modelparameters for any TFT model.

All of the measurement data is collected in one measurement sequence.

Current, conductance, or resistance can be selected for a measurement setas an optimization target for up to 40 different TFT geometries.

ALL_DC measurement data is a suitable target for regular or localoptimization strategies.

If ALL_DC data is stored in a data log file, it can be used as a source of datafor the IDS/VDS and ID/VGS routines.

Data Acquisition IDS vs VDS data set to be used for drain current IDS, output conductance gds,

or output resistance rds modeling is measured while VDS is swept over adefined voltage range for a set of VGS values.

IDS vs VGS data set to be used for drain current IDS and transconductancegm modeling is measured while VGS is swept over a wide voltage range (to

ensure that the device operates in the linear region) for a set of VDS values. The output resistance rds, output conductance gds, and transconductance

gm are internally computed from the measured drain current IDS.

After this computation, the data for all four potential optimization targets (draincurrent IDS, output resistance rds, output conductance gds, andtransconductance gm) becomes available for all measured geometries..)

TFT Capacitance Routines



- 8 6 -UTMOST

CGDO Gate To Drain Overlap Capacitance

extracts the CGDO model parameter.

Data Acquisition

The gate to drain voltage is swept from a large negative value

(typically -5V) to a large positive value (typically +5V).

The overlap structure is rather long, typically 1200 microns. This

produces an accurate measured capacitance with a typical value of

25pF to 70 pF.

CGD=W*CGDO

Others is same as CGDO

TFT Time Domain Routines



- 8 7 -UTMOST

ring_osc

The ring_osc routine reads oscillator period vs (tpd) data from an

oscilloscope, and displays the measured Tpd vs VDD data.

Data Acquisition

The user enters the VDD_start, VDD_step and #_of_steps for the

data collection.

Drain terminal should be connected to VDD, and Source terminal

should be connected to GND of the ring oscillator circuit.

The Output signal will be measured by the oscilloscope, and

UTMOST will read the "period" for each VDD step from the scope.

After the completion of all VDD steps, the Tpd vs VDD data will

be displayed.

Model Generation



- 8 8 -UTMOST

Supports widest selection of commercially available device models

Generates models for SmartSpice, HSPICE, Spectre and ELDO

Offers fast buit-in SPICE simulation library (SmartLib)

External SPICE mode allows you to connect to any SPICE simulator

Supports the conversion of model parameter sets from one model to

another Macro modeling and parameter extraction is available for devices

which cannot be adequately modeled by any existing device models

User-defined models linked dynamically

Support for SmartSpice interpreter models Fast simulation using SmartLib Model and Fast internal solver




- 8 9 -UTMOST

Model selection


Model IV/CV/Timing curves measurement Model parameters extraction

Model parameters QA

Model QA



- 9 0 -UTMOST

Check model curve RMS and Max Error

Check model parameters boundary, if any violation Physics Check the model continuity and quadratic differential

Check Convergence

Check Spice compatibility

Check Temperature Stability

Check voltage stability

Check geometry stability

SILVACO TFT Models



- 9 1 -UTMOST

SmartSpice currently supports 4 TFT device models

Level=15 ( Leroux Amorphous Model )

Level=16 ( Berkeley Polysilicon Model)+Leakage current Model

Level=35 ( RPI Amorphous Model ) ( Version=1 & Version=2)

Level=36 ( RPI PolySilicon Model ) ( Version=1 & Version=2)

RPISCALE=1 SMART=0,1,2,3 Model

SILVACO TFT Models



- 9 2 -UTMOST

MOS Geometry Model parameters

Parameter Description Units Default

ACM Area Calculation Method 0

DEL Channel length reduction (Level 1, 2, 3, and 6 only ) m 0

XJ Metallurgical junction depth m 0.15e-6

LD(DLAT,LATD) Lateral diffusion into channel from source and drain m 0.75*XJ

WD Lateral diffusion into channel from bulk m 0

LDIF Lateral diffusion beyond the gate m 0

HDIF Heavily doped diffusion length. m 0

XL(LDEL) Masking and etching effects on L m 0

XW(WDEL) Masking and etching effects on W m 0

DL(DL0) Channel length reduction ( Level 4, 5, and BSIM3 module only) um 0

DW(DW0) Channel width reduction ( Level 4, 5, and BSIM3 module only) um 0

GEO Source/drain geometry selector 0

Common Geometry and Bulk diode Model Parameters (ACM)

ACM=0 : Berkeley SPICE models ( pn bulk junctions and source (drain) resistors.

ACM=1 : ASPEC Model, Improved pn junction models ( high and low doping regions )

ACM=2 : Physical model, ( high and low doping regions device and is suitable for LDD

devices )

ACM=3 : ACM=2 extension ( shared source and drain MOSFET geometry )

SILVACO TFT Models



- 9 3 -UTMOST

Capacitance model pa rame ters

Parame ter Descr iption Units Default

CGDO Drain Overlap Capac itance factor F/m 0

CGSO Drain Overlap Capac itance factor F/m 0

Drain/Source resistance model parameters


RD Drain ohmic resistance

Ohm(ACM=0)

Ohm/sq (ACM =1,2,3) 0

RS Source ohmic resistanceOhm(ACM=0)

Ohm/sq (ACM =1,2,3)0

RDC Drain contact resistance Ohm 0

RSC Source contact resistance Ohm 0

RSH Drain, source diffusion sheet resistance Ohm/sq 0

SILVACO TFT Models



- 9 4 -UTMOST

Self Heating Thermal Model Parame ters


SHMOD(SELFT)

Self-Heating Selector 0

RTH0 Thermal Resistance C/W 0

CTH0 Thermal Capacitance W.s/C 0

Drain/Source resistance model parameters

Parameter Description Units DefaultRD Drain ohmic resistance

Ohm(ACM=0)Ohm/sq (ACM =1,2,3)

0

RS Source ohmic resistanceOhm(ACM=0)

Ohm/sq (ACM =1,2,3)0

RDC Drain contact resistance Ohm 0

RSC Source contact resistance Ohm 0

RSH Drain, source diffusion sheet resistance Ohm/sq 0

SILVACO TFT Models



- 9 5 -UTMOST

MOSFET models levels 1, 2, 3, 6, and 9Leff=L*SCALE*LMLT+XL*SCALM

-2(LD+DEL)*SCALEWeff=W*SCALE*WMLT*XW*SCALM

-2*WD*SCALMWeff*=W*SCALE*WMLT+XW*SCALM( for overlap cap calculation )

MOSFET models levels 1, 2, 3, 6, and 9Leff=L*SCALE*LMLT+XL*SCALM

-2(LD+DEL)*SCALEWeff=W*SCALE*WMLT*XW*SCALM

-2*WD*SCALMWeff*=W*SCALE*WMLT+XW*SCALM( for overlap cap calculation )

MOSFET models levels 4, 5, 7, 10, and 69Leff=L*SCALE*LMLT-2LD ( if DL is not define)

if DL is not specified,Leff=L*SCALE*LMLT+Xl*SCALM -2LD*SCALEif DW is define,

Weff=W*SCALE*WMLT-WD, Weff*=Weff.If DW is not specified,Weff=W*SCALE*WMLT+XW*SCALM-2WD*SCALWeff*=W*SCALE*WMLT+XW*SCALE

MOSFET models levels 4, 5, 7, 10, and 69Leff=L*SCALE*LMLT-2LD ( if DL is not define)

if DL is not specified,Leff=L*SCALE*LMLT+Xl*SCALM -2LD*SCALEif DW is define,

Weff=W*SCALE*WMLT-WD, Weff*=Weff.If DW is not specified,Weff=W*SCALE*WMLT+XW*SCALM-2WD*SCALWeff*=W*SCALE*WMLT+XW*SCALE

SILVACO TFT Models



- 9 6 -UTMOST

ACM=3

GEO = 0 : No sharing

GEO = 1 : Drain is shared with other devices

GEO = 2 : Source is shared with other devices

GEO = 3 : Both drain and source are shared

with other devices

default is GEO = 0

ACM=3

GEO = 0 : No sharing

GEO = 1 : Drain is shared with other devices

GEO = 2 : Source is shared with other devices

GEO = 3 : Both drain and source are shared

with other devices

default is GEO = 0

If AD is unspecified (ACM=2, ACM=3(GEO=0,2))ADeff=(2*HDIF*SCALE*WMLT*(Weff*))*M

If ACM=2 or ACM =3 and GEO=1, 3

ADeff=(HDIF*SCALM*WMLT*(Weff*))*M

else

ADeff=(AD*SCALE^2*WMLT^2)*M

If AS is unspecified ( ACM=2, or ACM=3 (GEO=0,1))ASeff=(2*HDIF*SCALM*WMLT*(Weff*))*M

if ACM=3, and GEO=2,3

ASeff=(HDIF*SCALM*WMLT*(Weff*))*M

else

ASeff=(AS*SCALM^2*WMLT^2)*M

If AD is unspecified (ACM=2, ACM=3(GEO=0,2))ADeff=(2*HDIF*SCALE*WMLT*(Weff*))*M

If ACM=2 or ACM =3 and GEO=1, 3

ADeff=(HDIF*SCALM*WMLT*(Weff*))*M

else

ADeff=(AD*SCALE^2*WMLT^2)*M

If AS is unspecified ( ACM=2, or ACM=3 (GEO=0,1))ASeff=(2*HDIF*SCALM*WMLT*(Weff*))*M


ASeff=(HDIF*SCALM*WMLT*(Weff*))*M

else

ASeff=(AS*SCALM^2*WMLT^2)*M

If PD is unspecified (ACM=2, ACM=3(GEO=0,2))PDeff=(4*HDIF*SCALE*WMLT*2(Weff*))*M

PDeff=2*HDIF*SCLM*WMLT*(Weff*)*M

If ACM =3 and GEO=1, 3

PDeff=(2HDIF*WMLT+(Weff*))*M

else PDeff=(PD*SCALE*WMLT)*M

If PS is unspecified ( ACM=2, or ACM=3 (GEO=0,1))

PSeff=(4*HDIF*SCALM*WMLT+2(Weff*))*M


PSeff=(2HDIF*SCALM*WMLT+(Weff*))*M

else PSeff=(PS*SCALM*WMLT)*M

If PD is unspecified (ACM=2, ACM=3(GEO=0,2))PDeff=(4*HDIF*SCALE*WMLT*2(Weff*))*M

PDeff=2*HDIF*SCLM*WMLT*(Weff*)*M

If ACM =3 and GEO=1, 3

PDeff=(2HDIF*WMLT+(Weff*))*M

else PDeff=(PD*SCALE*WMLT)*M

If PS is unspecified ( ACM=2, or ACM=3 (GEO=0,1))

PSeff=(4*HDIF*SCALM*WMLT+2(Weff*))*M


PSeff=(2HDIF*SCALM*WMLT+(Weff*))*M

else PSeff=(PS*SCALM*WMLT)*M

MOS diode Model for ACM=2 and ACM=3

SILVACO TFT Models



- 9 7 -UTMOST

If NRS is specified,

else,

If NRS is specified,

else,

If NRD is specified,

else,

If NRD is specified,

else,

M

RSC RSH NRS RS Weff

SCALM LDIF LD

RSeff )***

)(

M

Weff

RS SCALM LDIF LD RSH SCALM HDIF

RSC RSeff *

**)(**(

M

RDC RSH NRD RS Weff

SCALM LDIF LD

RDeff

)***

)(

M

Weff

RDSCALM LDIF LD RSH SCALM HDIF

RDC RDeff *

**)(**(

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Utmost TFT Training Part1