1.3
a) calculate an estimate of the number of 20-mm x 20-mm dice on
a 300-mm diameter wafer, in
terms of the total wafer and die areas.
Solution: din tch b mt wafer: x = 70685 )
Din tch mt vung 20 x 20 = 400 ( )
Vy c th ch to c s dice trn wafer 282743/400 = 176 ( dice )
b) calculate the exact number of 20-mm x 20-mm dice that
actually fit on the 300-mm wafer. (it may
help to draw a picture).
tnh chnh xc s lng dice l 148 dice
300mm 20mm
1.10 an 18-mm x 25-mm die is covered by an array of 0.25m metal
line separated by 0.25m wire
spaces.
a) what is the total length of wire on this die ?
rng ca dy v khong trng l 0.25 + 0.25 = 0.5 m
Ta xem nh metal i theo chiu dc l 25 mm
Vy theo chiu ngang, s dy metal c to 18000 / 0.5 = 36000
Tng chiu di dy metal 36000 x 25 = 900000 mm
b) how about 0.1-m line and spares.
rng ca dy v khong trng l 0.1 + 0.1 = 0.2 m
Tng chiu di dy metal 18000/0.2*25 =2250000 mm
2.1 A complex CMOS fabrication process require 25 masks
a) what fraction of the dice must be good (what yield must be
obtained)during each mask step if we
require 30% of the final dice to be good?
Sau 25 cng on th s dice tt cn li 30% ta s dng cng thc quy, gi s
dice tt trong mi
cng on l X ta c
100. = 30 => X = 95,298%
Vy mi cng on ta phi c 95,3% thnh phn t cht lng
b) how about if we require 70% to be good?
c c sn 70% sn phm c cht lng th
100. = 70 => X = 98,58 %
