maskrom auto fail bitmap monitoring algorithm & applied ... · dong seog chae swtw 2001 - slide...

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


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


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.


BitMap Analysis and Monitoring Method

Assortment target wafer

Test Start

Every 5th Wafer

BitMap routine Start

Redunduncy

Full Test Item Complete

Binning Decision

N


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


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


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


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


Applied Effect(Visual Inspection)

String Repair

W/L Bridge Gate Oxide


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


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


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


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

¡Ü

¡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


Limitation of 8 Bit RepairFail type Change(String Fail)-> Decrease Repair rate

-NAND Cell : 75% - FLAT Cell : Less than 5%


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


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


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


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


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)

maskrom auto fail bitmap monitoring algorithm & applied ... · dong seog chae swtw 2001 - slide...

Documents