03-devicescontd

8/9/2019 03-DevicesContd

1/13

!"#"$%& ()*!+,"#-*./(0123+4$56+ 7* !+8"4+, 49-:-5+;

V

T

n+ n+

n-channel

• G9"3 ! -+ -3#1"$+") $7(F" ! '

• '(1" 3"?$2F" .9$3 %(+-2F" #9$1?"+ $1"$H1$#.") #*(+" .( .9" ?$." I.013+ -3.( (8

./%" =$."1-$*J

• K #9$33"* -+ L(1=") I6.1(3? -3F"1+-(3J

p-l i

i

n+ n+

V GS> 0


2/13

LU ND UNI VER S I T Y

Lund University / Dept. of Electrical and Information Technology / September 4, 2014 - 5

!"#$%A M-3"$1 !"?-(3 I!"+-+2F" @%"1$2(3J

p-

DepletionRegion

V GS> V T

n+ n+

n-channel

I D

V DS

V T

n+

I D

V DS

=V GS

-V T

n+


3/13



2

2

0

´- ; ( - ) (1 )

2- ; ´ (( - ) - )(1 )

2

´

( -2 - -2 )

!

!

µ

" # #

$ = +

< = +

=

= + + SB

n

DS GS T D GS T DS

DS

DS GS T D n GS T DS DS

n n ox

T T F F

k W V V V I V V V

L

V W V V V I k V V V V

L

k C

V V V

!"#$%

Often added toavoid discontinuity

Equations widely used models for manualcalculations

saturation

linear


Lund University / Dept. of Electrical and Information Technology / September 4, 2014 - 1 0

;9$%."1 UV9" >"F-#"+ ;(3.P



K O1+. (1)"1 =()"* L(1 .9" F"*(#-./ +$.01$.")

1"?-(3A

'()"* L(1 '$30$* K3$*/+-+

2

(( ) )2

DSAT

DSAT n ox GS T DSAT V W I C V V V

Lµ = ! !

We will transform this model into its unified equivalent



K W3-O") '()"* L(1 '$30$* K3$*/+-+

2' min

min

min

(( ) )(1 )

2

min( , , )

D n GS T DS

GS T DS DSAT

W I k V V V

L

V V

V V V V V

! = " " +

= "


4/13



K W3-O") '()"* L(1 '$30$* K3$*/+-+

2'

' 2

2'

(( ) )(1 )2

( ) (1 )

Resistive

Saturated

Ve

2

(( locity saturated) )(1 )2

DS

D n GS T DS DS

n

D GS T DS

DSAT

D n GS T DSAT DS

V W I k V V V V

L

k W I V V V L

V W I k V V V V

L

!

!

!

= " " +

= " +

= " " +



45$=%*" X W3-O") '()"*

2'

6

inmin

2

m(( ) )(1 )2

172.5 10 ((1.5 0.4 0.63

0.633) )(1 0.06 1.5) 89.42

D n GS T DS

D

W I k V V V

L

I

V V

A

!

µ "

= " " +

= # " " + # =

V T = 0.43V ; V

DS =1.5V ,1V ; V

GS =1.5V ,1V ; V

DSAT = 0.63V ;

! =0.06; k n

' W min

Lmin

=115!10"6!

0.375

0.25=172.5µ A /V

2

min

min

min( , , )

min(1.5 0.43, 1.5, 0.63)

GS T DS DSAT V

V

V V V V = !

= !


5/13



K :'@6 V1$3+-+.(1

8\PZ 8\ 8[PZ 8[ 8YPZ Y 8YP[

8YPYa

8YPY`

8YPY]

8YPY\

Y

K++0=" $**

30=7"1+

3"?$2F"b

! _ 8[PY,

! _ 8[PZ,

! _ 8\PY,

! _ 8\PZ,

,"*(#-./ +$.01$2(3 -+ *"++ %1(3(03#") L(1 :'@6 )0" .( *(C"1

=(7-*-./ $" I=KJ

! "# I,J



V1$3+-+.(1 '()"* L(1 '$30$* K3$*/+-+

0 375 m

0 25 m

.

.

min

min

W

L

µ

µ

=

=

V$7*" (3 c$#D ;(F"1



V9" V1$3+-+.(1 $+ $ 6C-.#9

V DS (V)

I D (A)

V DD/2 V DD

VelocitySaturated

Req

Velocity

Saturated

ReqS

G

D

Problem: RON is time varying,

dependent on the operation

mode

6-=%*-O") =()"* $F"1$?"+ .9"

#011"3.+ (3 .9" "3)%(-3.+ (L .9"

.1$3+-2(3 1"?-(3 I%? [YZJ



V9" V1$3+-+.(1 $+ $ 6C-.#9

YPZ [ [PZ \ \PZ Y

[

\

U

]

Z

`

d

5 [YZ

! "" I,J

, -

.

I @

9 = J

Req depends on VDS


6/13



V9" V1$3+-+.(1 $+ $ 6C-.#9

V DD (V) 1 1.5 2 2.5

NMOS (k!) 35 19 15 13

PMOS (k!) 115 55 38 31

,-. 1"+-+.$3#" L(1 $ +T0$1" .1$3+-+.(1 I/01 _ [J

-3 YP\Z 0=

IV$7*" (3 c$#D ;(F"1J



C.)E0! E?!.? .FF.)/C

607 V91"+9(*) ;011"3.



6078V91"+9(*) !"?-(3

1 2 3

VGS

[V]

Sub threshold region

l n ( I

D )

VT

V9" +07 .91"+9(*) )1$-3

#011"3. 9$+ $3

"5%(3"32$* 1"*$2(3 .(

.9" ?$." F(*.$?"

I#(=%$1" .( 7-%(*$1JP

l n (

I D )

Logarithmic



0

GS T

T

V V

m v

off I I e

!

"

= "

V9" V1"3) -+ .( 1")0#" ! '

ln ( I D )

1 p

100 p

10 n

1 u

100 u

10 m

0 1 . 0 2 . 0 2 . 5 0 . 5 1 . 5

V GS ( V ) High V T

Low I off

Low V T

High I off

Exponential increase of thestatic power!

V T


7/13



! ' -3 69(1. ;9$33"* '@6

p-

n+ n+

p-

n+ n+

V9" >1$-3e6(01#"

>"%*"2(3 f9"*%+ .9"

#9$33"*g .( +.1(3?

-3F"1+-(3P

^3 $ +9(1. #9$33"* .9"

.91"+9(*) F(*.$?" ."3)+

.( 7" *(C"1P



The depletion regionincreases around the

drain when V DS increases

The effect can not beneglected in a shortchannel device

V T tends to be lower

! ' -3 $ 69(1. ;9$33"* '@6

p-

n+

n+

V DS = 0

p-

n+

n+

V DS = V DD



VDS

V T

L

V T

Short

Channel

! ' -3 69(1. ;9$33"* '@6

Long devices have ahigher VT and

consequently lower

leakage

Channel stretching is

effective for leakagereduction

Penalty: Speed



45$=%*"8 '"$+01"="3.+

-

29

!"#$ !"% !"%$ !"& !"&$

'!&

'!$

'!(

)**

+),

- . / 0 1 / 2 3 4 + 6 7 ,

!"#$ !"% !"%$ !"& !"&$'!

B'

'!!

'!'

)**

+),

8 2 / . 9 4 : ; < / . = > ? @ 2 + < A ,

C@>=D 82/.94

*42=E?3 82/.94

F/=G=9/ 82/.94

" " " " "

. . .

K 1"L"1"3#" #-1#0-. C$+

="$+01") -3 .9" +078,V

)(=$-3 ,>> h ZYY=,

@F"1 ]YY DBN $. ]YY=,


8/13



SECOND ORDER EFFECTS

;$%$#-.$3#"



;$%$#-.$3#"

• VC( V/%"+ (L ;$%$#-.$3#"

• i03#2(3 ;$%$#-.$3#"

•

>-()" $1"$+• ;(3.1-702(3 L1(= .C( %$1.+ 8 $1"$ $3) +-)" C$**

• j$." ;$%$#-.$3#"8

j$." .( c0*D

8 j$." .( 6(01#"e>1$-3



DrainSource Gate

CDB

n+n+

CG

CGD

CGS

CSB

Xd

tox

'@6 ;$%$#-.$3#"+

c0*D ;$%P

i03#2(3 ;$%P

@F"1*$% ;$%P

. , . ,

:

,

.,

. . . - ,

. .

, + -

- +.

, .

- , .

. . . -

,

.

, ,

.

,

- - 1. - 1 - . . 1 1 .

3

1 1

i

; ,

-

. .

Side wall

Bottom

Side wall

Substrate N A

Source N D

Channel-stop implant

A+

LS

W

Channel

.

x j

.



n+ n+

Cut off

n+ n+

Linear

n+ n+

Saturation

j$." ;$%$#-.$3#"

V9" ;$%$#-.$3#" #9$3?"+ C-.9

.9" (%"1$2(3 =()"

09-&"-+%6 G+=%8"96


9/13



>/3$=-# ;$%$#-.$3#"

-

-

-

.

V T

C GC

C GCS = C GCDC GCB

WLC ox

WLC ox

2

V GS

-

-

-

.

WLC ox

WLC ox

2

2WLC o x

3

C GC

C GCS

V DS / (V GS -V T )

C GCD

0 1

j$."8c()/ ;$%$#-.$3#"

7"#(="+ Y C-.9 $

#(3)0#23? #9$33"*

j$."8>1$-3

;$%$#-.$3#"

7"#(="+ Y C-.9

+$.01$2(3

,>6k Y,,>6_Y

V(.$*

;$%$#-.$3#"



i03#2(3 ;$%$#-.$3#"

2 "34 ) 2 567 8 2 #/

!9-H$ 495-$ $=+ I%&&

$9I%6;, $=+ 4=%--+&

Drain/Source Diffusion

T o w a r d s

C h a

n n e l

Side

Wall

Bottom

G a t e

W

L



i03#2(3 ;$%$#-.$3#"

2 934 ) 2 :6;6

2 :6;6 -3 (3m. #(03. .9" C$** .(C$1)+ .9" #9$33"* -3.( .9" %"1-="."1



i03#2(3 ;$%$#-.$3#"

• 2 ? e2 ?=> -+ )"%"3)"3. (3 .9" 70*D F(*.$?"

• 2 ?@ $3) !Y $1" %1(#"++ %$1$="."1+

01

/ 2

0

01

/ 3

0

1

(1 )

1

(1 )

bottom j j

BD BS

sw jsw jsw

BD BS

C C Area C AreaV

C C Perimeter C Perimeter

V

!

!

= " = "

#

= " = "

#

Abrupt junction

Graded junction

Abrupt vs graded junction is discussed

in the book (Diode)


10/13



2 & ) 2 6A ! / ! 1-4

2 & )"%"3)+ (3 .9" 1"?-(3

2 6A -3 1$-3e+(01#"

1"?-(3



;9$33"* ;$%$#-.$3#"

;0. (SA R( #9$33"*" 2 &2 ) 2 &25

!"+-+2F"A ;9$33"*" >-F-)" 2 &2 -3 .C( %$1.+

6$.01$2(3A # \eU (L ;9$33"* .( +(01#"

(Table 3-4) To Bulk To Source To Drain Total Gate Cap.

C GCB

C GCS

C GCD

C G

Cutoff C OX W L 0 0 C OX W L + 2 C 0W

Resistive 0 (1/2) C OX W L (1/2) C OX W L C OX W L + 2 C 0W

Saturation 0 (2/3) C OX W L 0 (2/3) C OX W L + 2 C 0W

@F"1*$%

;$%$#-.$3#"

I%? [YdJ



'@6 ;$%$#-.$3#" 45$=%*"

j$." ;$%$#-.$3#" 8 YPUZ =-#1(3 %1(#"++

2 6A _ ]P` L


11/13



i03#2(3 ;$%$#-.$3#"

m =

1

2 for abrupt and m =

1

3 for graded junction

0

1

2

3

4

-5 -2 0.6

V D (V)

C (fF)

0-1-3-4

Abrupt

Graded

C j =

C j0

(1!V D"

0

)m



M-3"$1-N") i03#2(3 ;$%$#-.$3#"

09-&"-+%6 G+=%8"96A !"%*$#" 3(38*-3"$1 #$%$#-.$3#" 7/ $

*$1?"8+-?3$* "T0-F$*"3. *-3"$1 #$%$#-.$3#"P

>-+.1-70."+ "T0$* #9$1?" (F"1 .9" F(*.$?" +C-3? (L -3."1"+.

See page 83

0

1 1

0 0 0

( ) ( )

[( ) ( ) ]

( )(1 )

j j high j low

eq eq j

D high low

m m m

high low

eq

high low

Q Q V Q V C K C

V V V

V V K

V V m

! ! ! " "

# "= = =

# "

" " " "=

" "

Vhigh: upper voltage

Vlow : lower voltage



'@6 >"#(0%*-3? ;$%$#-.(1

VDD

Filters noise onthe supply lines



R(-+" (3 60%%*/ !$-*+

V9" C(1*) -+ 3(. )-?-.$*P G" 3"") .(

D3(C .9" *-=-.$2(3+

ISwitch

V DD

V

VDD

RWire

• K 7-? %1(7*"= (3 *$1?"+/3#91(3(0+*/ #*(#D") #9-%+

• @3 #9-% )"#(0%*-3?

#$%$#-.(1+ 9"*%+I# [e[Y (L .9" +C-.#9") ;J


12/13


13/13



V/%-#$* ,$*0"+ IYPUZµ=J

Parameter NMOS PMOS Discrete (BF 170)

k' 175 uA/V2 - 60 uA/V2 50 mA/V2

V T 0.50 V - 0.60 V 2 V

Leff 0.30 um 0.38 um

W eff 0.55 um 0.55 um! 0.58 V1/2 - 0.45 V1/2

" 0.05 - 0.15

t ox 7.5 nm 7.5 nm

C ox 4.6 fF/um2 4.6 fF/um2

C j0 0.93 fF/um2 1.42 fF/um2

C jsw0 0.28 fF/um 0.38 fF/um



…..

6"=-3$1A >1$-3 #011"3.o (%"1$2(3o =()"o %$1$+-2#+

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