Post on 18-Feb-2020
Dong Seog Chae SWTW 2001 - Slide 1
Maskrom Auto Fail Bitmap Monitoring Algorithm & Applied Effect in
Mass Product
Dong Dong Seog ChaeSeog Chae
Jun 03 2001Jun 03 2001
Samsung ElectronicsSamsung Electronics
Dong Seog Chae SWTW 2001 - Slide 2
Auto Fail BitMap Monitoring Method
Agenda
• Purpose of Auto Fail BitMap Setup In Mass Product
• BitMap Analysis and Monitoring Method• Fail Bit Analysis Result• Applied Effect
Dong Seog Chae SWTW 2001 - Slide 3
Purpose of Auto Fail Bitmap Setup In Mass Product
• For maintain Static Device Yield.• Rapid feedback to FAB about device
main fail type.• Decision of New Repair Scheme.• Save the manufacturing cost.
Dong Seog Chae SWTW 2001 - Slide 4
BitMap Analysis and Monitoring Method
Assortment target wafer
Test Start
Every 5th Wafer
BitMap routine Start
Redunduncy
Full Test Item Complete
Binning Decision
N
Dong Seog Chae SWTW 2001 - Slide 5
BitMap Analysis and Monitoring Method
Flow Chart B i t M a p S t a r t
F a i l A d d r e s s C o u n t &F a i l A d d r e s s S c a n
F a i l A d d r e s s S t o r e
E x i s t F a i l R o u t i n eO u t
U s e r S c r a m b l e ¡æB i t M a p S c r a m b l e
N
F a i l T y p e s E x t r a c t
F u l l C h i p T e s t
G e n e r a t e D a t af o r M a c s s y s t e m
G e n e r a t e r o w d a t a&
Y
C o n s t r u c t C o u n t T a b l e
• Address Store
• User scramble
Physical Scramble
• Fail type extract
• Store to Global DB
Dong Seog Chae SWTW 2001 - Slide 6
Fail Type Definition
• Only 1 or 2 Fail Address Fail BitSingle Bit Fail
• More than 30 Address Fail Bit at X AddressWore Line Fail
• Data 0 or 1 Fail / More than 2 String(0x20)• More than 30 Address Fail Bit
Bit Line Fail
• Data 1 Fail / Between 1 ~ 2 String Fail (0x20~0x3F)• More than10 Address Fail Bit
Contact Not Open
• Data 1 Fail / Less than 1 String (0x1F)• More than 5 Address Fail Bit
BN+ Open
• Data 0 Fail / Less Than 1 String (0x1F) • More Than 5 Address Fail Bit
Gate Oxide
DefinitionFail Type
Dong Seog Chae SWTW 2001 - Slide 7
Fail Bit Analysis Result(Fail Type/Per Chip)
LotID WaferID X,Y FAILBIT GOX BN+ CON WL XDEC BL SINGLEBMWG2828 W01 37,32 19 0 1 0 0 0 0 0BMWG2828 W01 38,32 169 2 1 0 0 0 1 1BMWG2828 W01 39,33 226 0 0 0 2 0 0 0BMWG2828 W01 38,33 16 1 0 0 0 0 0 0BMWG2828 W01 29,33 98 1 0 1 0 0 0 0BMWG2828 W01 30,33 82 1 0 0 0 0 0 1BMWG2828 W01 29,34 8430 0 0 0 0 0 1 0BMWG2828 W01 30,34 117 1 0 0 0 0 0 0BMWG2828 W01 35,34 125 2 0 0 0 0 0 1BMWG2828 W01 36,34 132 2 0 0 0 0 0 1
Dong Seog Chae SWTW 2001 - Slide 8
Fail Bit Analysis Result(Raw Data of Fail/Per Chip)
X: 0030
Y: 0030
FAILBIT: 232
GOX: 1
BN+: 0
CONATCT: 0
WORDLINE: 1
XDECODER:0
BITLINE: 0
SINGLE: 0
Xadd Yadd FailIO FailData Fail Pattern
=============================================
282 3A6 8 0 GOX
287 3A6 8 0
281 3A6 8 0
288 3A6 8 0
28A 3A6 8 0
Chip Inform
Fail Type
Fail Addr
Dong Seog Chae SWTW 2001 - Slide 9
Applied Effect(Visual Inspection)
String Repair
W/L Bridge Gate Oxide
Dong Seog Chae SWTW 2001 - Slide 10
Applied Effect(Fail Trend Plot)
0
20
40
60
80
100
120
140
160
180
200
B01
B01
B08
B09
B11
B12
B21
B22
B26
B26
B26
B26
B28
B34
B34
B34
C12
C14
C24
Lo t No
Fail
Cou
nt
GOX
BN+
Cont
W/ L
B/ L
X- de c
Si ngl e
Dong Seog Chae SWTW 2001 - Slide 11
Hit Ratio(MS3490 & BitMap Analysis)
85.410411127Total
----57Other
83.75043Single Bit
93.5173185Word Line
91.8317293Bit Line
91.71112ContactNot Open
89.1204229BN+ Open
93.1257276Gate Oxide
Hit RatioBitMap Tool(GII)
Exist ToolMS-3490
Fail Types
Dong Seog Chae SWTW 2001 - Slide 12
Derivation (Repair Scheme)• MaskRom Repair Scheme Change
(8 Bit Repair -> 8 String Repair)Fail Type Change (Extract Data from BitMap Algorithm)
Fai l TypeSt ri ng Fai l
W/ L B/ L Bi t Ot herGOX B/ N+
Act i veBri dge
NAND Cel l 7. 3 - - - - 9. 2 32. 5 27 15 9Nor Cel l 23. 8 20. 4 4. 4 12. 7 8. 1 18. 6 12
Dong Seog Chae SWTW 2001 - Slide 13
Cell Scheme ChangeNor CellNand Cell
¡Ü¡Ü
SSL<0>
SSL<1>
WL<15>
WL<0>
WL<14>
¡Ü
¡Ü
¡Ü
WL<1>
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
BL<0> BL<1>
¡Ü
¡Ü
¡Ü
¡Ü ¡Ü
¡Ü
¡Ü
BL<0> GL<0>
GSL<1>
GSL<0>
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü¡Ü¡Ü¡Ü ¡Ü¡Ü ¡Ü¡Ü ¡Ü¡Ü ¡Ü¡Ü
¡Ü ¡Ü ¡Ü¡Ü
¡Ü
¡Ü ¡Ü
¡Ü
¡Ü ¡Ü
¡Ü
¡Ü ¡Ü
¡Ü
¡Ü ¡Ü¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü
¡Ü ¡Ü
¡Ü
¡Ü ¡Ü
¡Ü
¡Ü ¡Ü¡Ü¡Ü
¡Ü
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¡Ü ¡Ü
¡Ü
¡Ü ¡Ü
¡Ü
¡Ü ¡Ü¡Ü
¡Ü
¡Ü
¡Ü
¡Ü¡Ü
¡Ü
¡Ü ¡Ü
WL<31>
WL<30>
SSL<0>
SSL<1>
WL<0>
¡Ü
¡Ü
¡Ü
WL<1>
¡Ü
¡Ü
¡Ü
Dong Seog Chae SWTW 2001 - Slide 14
Limitation of 8 Bit RepairFail type Change(String Fail)-> Decrease Repair rate
-NAND Cell : 75% - FLAT Cell : Less than 5%
Dong Seog Chae SWTW 2001 - Slide 15
Number of Fuse (String Red vs Bit Red)
•Z = N*2(α+32) @ String Repair
•N=2n(α+6) @ Bit Repair Scheme
•Z: Fuse No for String/Bit Repair
•α:String Add Fuse + I/O Fuse
•N: Number of Fail String
•n: Number of Fail Bit0
100
200
300
400
500
600
700
1 2 3 4 5 6 7 8Number of Fail Bit (EA)
Fus
Bit
1 String
2 String
3 String
4 String
5 String
6 String
Dong Seog Chae SWTW 2001 - Slide 16
String Repair Algorithm Flow ChartSt a r t
Ch e c k ECR
De Sc r a mb l e
So r t Da t a
Ana l Fa i l
DBM Da t a Ca t c h
ECR Da t a Ca t c h
Fi n a l Da t a Ex t
Y
u _ a c t i v e ( d u t ) N Re l a yOp e n
Pa s s / Fa i l
Dong Seog Chae SWTW 2001 - Slide 17
String Redundancy using ratio(64M X 16 B-Die)
(Normal YLD & Low YLD)
Normal YLD Low YLD
50 . 99%
28. 29%20. 72%
s t r i ng bi t s t r i ng+bi t
63. 8
16. 78%
s t r i ng bi t s t r i ng+bi t
Dong Seog Chae SWTW 2001 - Slide 18
Derivation(Repair Scheme)
0
5
10
15
20
25
30
16M E 16M F 32M E 64M B 64M C 128MA
64M A 128MM
Rep
0102030405060708090100
Yie
Repair PortionYield
Bit Re pair
String Re pair
0
5
10
15
20
25
30
32M E 64M B 64M C 64M A 128M M
Rep
0
10
20
30
40
50
60
70
80
90
100
Yie
RepairPortionYield
Bit RepairString Repair
Normal YLD Abnormal YLD
Dong Seog Chae SWTW 2001 - Slide 19
Results
• Average YLD Up (15% Up -> Repair Portion elevation)
• Obtained the static objected Data &Utilize at anytime.
• Real Time Fail Analysis & Feed Back. • Customer order meets(An Order Product)
(Possible to forecast device yield)