CMOS 0 (1) - 名大の授業 (NU OCW)ocw.nagoya-u.jp/files/123/r_note13.pdfBvB®Bt5 ö V DD C S 2 C L B V DD 2 V=V DD , 0 C L C S V S V DD 2 C L Q L =C L V DD /2 Q S =:çC S V DD /2

13-1

CMOS (1)

13-2

SRAM(Static Random Access Memory)

DRAM(Dynamic Random Access Memory)

FLASH

CPU

13-3

n

m

1bit

4Gbits = 232 bits= 65,536 x 65,536

(Minimum Feature Size)F = ( )/2

2F

1

13-4

= 9F x 6.5 F = 58.5 F2

SRAM DRAM FLASH

6 - 8 F2 4 - 10 F2130 F2

13-5

/4G1G

256M64M16M

4M1M

256K64K16K

4K1K

2561970 1980 1990 2000

DRAM

SRAM

FLASH

SRAM

DRAM

13-6

WL

SRAMStatic Random Access Memory

32M /FLASH, DRAM

BL BL

13-7

V V

V

V

0 VDD

VDD

VV

V

V

0 VDD

VDD

V

V

0 VDD

VDD

VV

V2 = f (V1) V2 = f -1(V1)

13-8

V

V

0 VDD

VDD

Static Noise Margin

Vn

+

Vn

+

Vn

+

-Vn

+

Vn

+

static noise margin

1

13-9Static Noise Margin

VDD

VWL = VBL = VBL = VDD

MD

MT

MT

MD

vOUTvIN

vIN

vOUTLow

MT 11

D TOUT DD Tn

D T

v V V

0

Static noise margin D / T

D / T

11

D T

D T

13-10DRAM(Dynamic Random Access Memory)

NN

0.1

8G /

13-11

VS = VDDCS

2(CL+CS)~VDDCS

2CL

VDD

2

V=VDD , 0

CSCL

VSVDD

2

CL

QL=CLVDD /2

QS = CSVDD /2

CS CL CS

VDD /2 VDD /2 VDD /2

VDD /2

precharge charge sharing

13-12

SC

S/N

6F2 8F2

2DDV

L H

2DDV

A

B

A, B 2A B

13-13

CL

(fF), CS

(fF), A

(m

2 ), V

S(V

) 104

103

102

101

100

10-1

10-2

16K 256K 4M 64M 1G 16G

CL

CS

AVS

( / )

DRAM

CS

CL

VSVDD2

cell area

VS ~ VDDCS2CL

CL

13-14

3D capacitor

13-15

High Dielectric Constant Materials

Relative Permittivity

Brea

kdow

n Fi

eld

Stre

ngth

(V/c

m) 107

106

105

1 10 100 1000

SiO2

Si3N4

Al2O3

Nb2O5

ZrO2

Ta2O5

TiO2

BST

0.1 10

SiO2 Equivalent Thickness (nm)

100

10

0.1

Insu

lato

r Rea

l Thi

ckne

ss (n

m)

t iteff

BST

SiO2

Si3N4

Al2O3

Nb2O5

ZrO2

Ta2O5

TiO2

1

1

13-16

TiN/Al2O3-HfO2

DRAM

Y. K. Park, et al., J. Korean Phys. Soc., Vol. 44, pp. 112, 2004

13-17

1978 (He++)

1996 ~ 20 /cm2 h

LSI < 1000 FIT114 1

1FIT (failures in time) = 10-9 / hour

Funneling

QD

QF

QDF

QD+QF

QDF

t~100ps

N+

P

10~100 fC/ m

Q ~ 10 fCt ~ 10 psI ~ 1 mA

SRAM

13-18FLASH

64G /

SRAM,DRAM10

SRAM, DRAM

13-19

EC

EV

EC

EV

x

y

y x

3.2eV

13-20

VCG

VDVS

CCVFG

0th thC

QV Q VC

Q

Q = QH Q = QL < QH

VCG

VDVS

Q

0 VCG

ID

chFGGCGFGC VVCVVCQ

Vth

( VFG , Vch VCG

13-21

NOR NAND

8

2

FLASH

13-22NOR FLASH (1)

5V1V 0V

0V

Q = 0 Q < 0

0 VCG

ID

5V0V

OPEN

0V

VCG (15V) VD(15V)

VS(0V)

> 3.2eVSiO2

0V/15V15V

0V 0V

~10 s ~ 10ns

SD

13-23NOR FLASH (2)

OPEN0V

VCG (0V) VD(open)

VS(15V)

Fowler-Nordheim

15V

OPEN

0V

~ 100ms

SD

13-24

yes

no

Verify

13-25NAND FLASH

10V

10V

10V

0V

18V

7V/0V

0V

20V

0V

0V

20V

0V

OPEN

20V

5V

5V

5V

5V

0V

5V

0V

13-26

C1 C2 Cn-1 Cn

D1 D2 D3 DnVDD

VSSCLK

VOUT = VDD + n (VDD VSS VTn)

=

13-27

FLASH

MONOS (Metal-Oxide-Nitride-Oxide-Semiconductor)

13-28

FLASH

~10

~ 10

~10nm