Transcript
Appendix 16: Equation Sheet Chapter 1: Review of Modern Physics 1.2. Quantum mechanics
h p
E ph h
hc
2 d 2 ( x) V ( x ) ( x ) E ( x ) 2m dx 2
h2 n 2 ( ) , with n 1, 2, ... En * 2m 2 L x
En
m0 q 4 8 02 h 2 n 2
1.3. Electromagnetic theory dE ( x ) ( x ) dx
d 2 ( x ) dx 2
d ( x ) E ( x ) dx
( x)
A16-1
, with n 1, 2, ...
Chapter 2: Semiconductor Fundamentals 2.3. Energy bands E g (T ) E g (0)
T 2 T
2.4. Density of states g c (E)
1 dN 8 2 * 3 / 2 m E E c , for E E c L3 dE h3
g c ( E ) 0, for E E c
2.5. Carrier distribution functions f (E)
1 1 e
( E E F ) / kT
f donor ( E d )
1 1 1 e ( E d E F ) / kT
f acceptor ( E a )
2
f BE ( E )
1
f MB ( E )
e ( E EF ) / kT 1
1 1 4e
( Ea E F ) / kT
1 e ( E EF ) / kT
2.6. Carrier densities
no
g c ( E ) f ( E )dE
po
no N c e
E F Ec kT
ni N c N v e
Ei
g v ( E )[1 f ( E )]dE
Ec
2 2 m* no 3 2 2
Ev
3/ 2
( E F E c ) 3 / 2 , for E F E c and T = 0 K
with N c 2 [ E g / 2kT
2 me* kT 3 / 2 ] h2
po N v e
Ev E F kT
n o p o n i2
Ec Ev 1 N E Ev 3 m* kT ln( v ) c kT ln( h* ) Nc 2 2 2 4 me
A16-2
with N v 2 [
2 mh* kT 3 / 2 ] h2
no ni e ( EF Ei ) / kT
p o ni e ( Ei EF ) / kT
n E F E i kT ln o ni
p E F E i kT ln o ni
E c E d 13.6
no
N d N a 2
* m cond
m 0 r2
eV
N d N a 2 ( ) ni2 2
n no n ni exp(
Fn Ei ) kT
N a N d N a N d 2 po ( ) ni2 2 2
p p o p ni exp(
Ei F p kT
)
2.7. Carrier Transport | v | q |E | m
min
J qn n E
J q nv e q p v h q ( n n p p ) E
J
E
q(n n p p )
v (E )
1
N 1 ( ) Nr
1 q(n n p p )
E E
1
J n q Dn Dn n
max min
v sat
dn dx
J p q D p
kT nVt q
J n qn n E q Dn
dn dx
Dp p
dp dx
kT pVt q
J p q p p E q D p
I total A( J n J p )
A16-3
dp dx
2.8. Carrier recombination and generation U n Rn Gn
n p n p0
p pn0 U p Rp Gp n
n
p
pn ni2
N t vth Ei Et p n 2ni cosh( ) kT
U b b b( np ni2 )
U SHR
U Auger n n(np ni2 ) p p(np ni2 )
G p ,light G n,light
d Popt ( x) dx
Popt ( x) E ph A
Popt ( x)
2.9. Continuity equation n ( x, t ) 1 J n ( x, t ) Gn ( x, t ) Rn ( x, t ) q t x
J p ( x, t ) p ( x, t ) 1 G p ( x, t ) R p ( x, t ) q x t
2 n p ( x , t ) n p ( x, t ) n p 0 n ( x, t ) Dn t n x2
2 p n ( x, t ) p n ( x, t ) p n 0 p ( x, t ) Dp t p x2
0 Dn
d 2 n p ( x) dx
2
n p ( x) n p 0
d 2 p n ( x)
0 Dp
n
dx
2
p ( x) p n0 n
p
2.10. The drift-diffusion model q( p n N d N a )
dE dx
d E dx
dE i qE dx
n ni e ( Fn E i ) / kT
p ni e
J n qn n E q Dn Jn 0 1 q x
dn dx np ni2
( E i F p ) / kT
J p q p p E q D p
1
E Ei ) n p 2ni cosh( t kT
01 q
A16-4
Jp x
dp dx np ni2
1
E Ei ) n p 2ni cosh( t kT
Chapter 3: Metal-Semiconductor Junctions 3.2. Structure and principle of operation B M , (n-type semiconductor) , i M
Ec E F , n , q
n - type
B
Eg q
M , (p-type semiconductor)
i
Ec E F , p q
- M ,
p - type
3.3. Electrostatic analysis d 2 dx 2
d 2 dx 2
q ( p n N d N a ) s s
2q ni
s
(sinh
( x ) qN d
E ( x)
F Vt
0 x xd ,
qN d
s
(x d - x)
E ( x) 0
E ( x 0)
xd
sinh F ) Vt
0 x xd xd x
qN d x d
s
Q d
s
2 s ( i V a ) qN d
N a N d sinh F Vt 2ni and ( x ) 0
( x) ( x)
xd x
qN d 2 [ x d (x d -x) 2 ] 2 s qN d x d2
xd x
2 s
i V a ( x 0)
Cj
dQ d dV a
0 x xd
qN d x d2 2 s
q s N d s 2( i V a ) x d
3.4. Schottky diode current V J n q n E max N c exp( B )[exp( a ) 1] Vt Vt
B
V J n qv R N c exp( )[exp( a ) 1] Vt Vt
E max
vR
J n q vR n
A16-5
2q (i Va ) N d
s
* 3/ 2 kT 4 2qm B and exp E 2 m 3
3.5. Metal-Semiconductor Contacts 3.5.1. Contact resistance to a thin semiconductor layer d 2 I ( x) I ( x) 2 with dx 2
I ( x) I 0
sinh
c Rs
V ( x) I 0
d
Rs W
coth
W
Rs
dx
sinh
Rc
c
d
R2
c Rs W
cosh
dx
sinh
Rs
d
L , for d >> W
3.6. Metal-Semiconductor Field Effect Transistor (MESFETs) VT i
qN d d 2 i VP 2 s
I D q n N d d
I D , sat
2 ( VG V D ) 3 / 2 ( i VG ) 3 / 2 W V D i 3 L V VP P
(i VG ) 3 / 2 W 2 q n N d d VG VT 3 VP L VP
for VG > VT
with V D , sat VG VT
Chapter 4: p-n Junctions 4.2. Structure and principle of operation i Vt ln
Nd Na ni2
i Va
4.3. Electrostatic analysis of a p-n diode xd xn x p
q ( p n N d N a ) q ( N d N a ), for x p x x n
A16-6
, for x x p
( x) 0 ( x) qN a ( x) qN d ( x) 0
, for x p x 0 , for 0 x xn , for xn x
Q n qN d x n
Q p qN a x p
dE(x) ( x ) q ( N ( x ) N a ( x )), for x p x x n dx s s d
E ( x) 0
E ( x) E ( x)
, for x x p qN a ( x x p )
, for x p x 0
s
qN d ( x xn )
, for 0 x x n
s
, for x n x
E ( x) 0 E ( x 0)
qNa x p
s
q N d xn
s
E ( x 0)
2( i Va ) xd
N d xn N a x p xn xd
Na Na Nd
i Va
q N d xn2 2 s
Nd Na Nd
x p xd
q N a x 2p 2 s
xd
2 s 1 1 ( )( i Va ) q Na Nd 2 s N d 1 ( i Va ) q Na Na Nd
xn
2 s N a 1 ( i Va ) q Nd Na Nd
xp
Cj
q s Na Nd 2( i Va ) N a N d
Cj
s xd
4.4. The p-n diode current p n ( x xn ) p n0 eVa / Vt
n p ( x x p ) n p 0 eVa / Vt
A16-7
pn ( x xn ) pn 0 Ae
( x xn ) / L p
n p ( x x p ) n p0 Ce
Be
( x x p ) / Ln
( x xn ) / L p
De
( x x p ) / Ln
p n ( x x n ) p n 0 p n 0 (e Va / Vt 1)[cosh
n p ( x x p ) n p 0 n p 0 (e
Va / Vt
L p D p p Ln Dn n
x xn w' x xn ] coth n sinh Lp Lp Lp
1)[cosh
x xp Ln
coth
w 'p Ln
sinh
x xp Ln
]
w'p w p x p
wn' wn xn
I A[ J n ( x x p ) J p ( x xn ) J r ] I s (eVa / Vt 1)
I s q A[
I s q A[
Dn n p 0 Ln Dn n p 0 Ln
coth(
w'p Ln
D p pn0 Lp
)
D p p n0 Lp
wn' coth( )] (general case) Lp
] (“long” diode)
J bb qni2 bw(eVa / Vt 1)
I s q A[
J SHR
Dn n p 0 w 'p
D p pn0 wn'
] (“short” diode)
qni x ' Va / 2Vt (e 1) 2
V a * V a IR s
J J s e Va / Vt
1 log(e) slope Vt slope 59.6 mV/decade
Q p I s , p (eVa / Vt 1) p
I s, p q
Cd , p
Cd , p
I s , p eVa / Vt p Vt
I s , p eVa / Vt t r , p Vt
A pn 0 D p Lp
(“long” diode)
(“short” diode)
with t r , p
A16-8
w 'p
2
2D p
4.5. Reverse bias breakdown E br
4 x10 5 V/cm 1 13 log( N / 1016 cm - 3 ) 2
E Vbr i br s 2qN 1
M
V 1 a Vbr
n
x d ,br
E br s qN
, where 2 n 6
4 2 m* E 3 / 2 g exp 3 q E
J n q vR n
4.6. Optoelectronic devices I I s (eVa / Vt 1) I ph
I ph,max
q Pin h
I ph (1 R)(1 e d )
i 2 2 q I f
I V Fill Factor m m I scVoc
Roundtrip amplification e 2 gL R1 R2 1
g
Pout
qPin h
1 1 ln 2 L R1 R 2
h ( I I th ) q
Chapter 5: Bipolar Junction Transistors 5.2. Structure and principle of operation w B' w B x p, BE x p, BC
w E' w E x n, BE
wC' wC x n, BC
x n , BE
2 s ( i , BE V BE ) N B q NE
1 NB NE
x p , BE
A16-9
2 s ( i , BE VBE ) N E q NB
1 NB NE
2 s ( i , BC VBC ) N C q NB
x p , BC
i , BE Vt ln
1 N B NC
NB NE
2 s (i , BC VBC ) N B 1 q N C N B N C
xn , BC
i , BC Vt ln
ni2
N B NC ni2
I E IC I B
I E I E ,n I E , p I r ,d
I C I E ,n I r , B
I B I E , p I r , B I r ,d
IC IE
IB
I E ,n I r , B
r
IE,n
1
I E.n I E ,n I E , p
E
T E r
T
IC
I E I r ,d IE
5.3. Ideal transistor model D n, B I E ,n qni2 AE N w' B B ni2 Qn, B q AE NB I E ,n
w' V exp( BE ) 1 B Vt 2
I r,B
tr
n
2
w B' 1 T 1 n 2 D n, B n
Dn, B N E w E'
D p, E N B w B'
Q n, B
tr
D p, E N B w B'
D n, B N E w E'
exp(V BE ) 1 Vt
w' tr B 2 D n, B
1 1
D p, E I E , p qni2 AE N w' E E
2
Qn, B
E
exp(V BE ) 1 Vt
, if E
A16-10
VA
QB C j , BC
qN B wB'
s
x p , BC x n , BC
n
V 1 1 t C j , BE d ln I C QB Vt dVBE
A16-11
Chapter 6: MOS Capacitors 6.3 MOS analysis VFB M S M S M
Eg
Vt ln(
2q
Poly-silicon: poly S Vt ln(
V FB MS
Eg Na N Vt ln( d ) (pMOS) ) (nMOS) M S M 2q ni ni N a, poly Na
) (p-type) poly S Vt ln(
Qi 1 tox ox ( x) x dx C ox ox 0
Qinv C ox (VG VT ) for VG VT
F Vt ln
Na (nMOS) ni
VG V FB s
VG V FB s
xd
C ox
C ox
4 s qN a F Cox
x d ,T
(nMOS)
1 x 1 d ,T Cox s
Nd (pMOS) ni (nMOS)
(pMOS)
4 s F qN a
VT V FB 2 F
4 s qN d F C ox
(pMOS)
1 C LF C HF , for VFB VG VT xd 1 Cox s
C LF C HF C ox , for VG VFB
C LF Cox and C HF
t ox
for VFB > VG > VT and 0 s 2 F
2 s s , for 0 s 2 F qNa
) (n-type)
ox
for VFB < VG < VT and 0 s 2 F
2 s qN d s
N d , poly N a
Qinv 0 for VG VT
F Vt ln
2 s qN a s
VT V FB 2 F
with C ox
ni2
, for VG VT
C FB
A16-12
1 L 1 D Cox s
with LD
s Vt qN a
Chapter 7: MOS Field Effect Transistors 7.3. MOSFET analysis Linear model
I D C ox
W (VGS VT )V DS , for | V DS | (VGS VT ) L
Quadratic model
ID
V DS2 W C ox [(VGS VT )V DS ] , for V DS VGS VT L 2
I D , sat C ox
2 W (VGS VT ) , for V DS VGS VT 2 L
g m, quad C ox
W V DS L
g m, sat C ox
g d , quad C ox
W (VGS VT V DS ) L
g d , sat 0
W (VGS VT ) L
Channel length modulation W (VGS VT ) 2 I D, sat Cox ( 1 V DS ) , for VDS VGS VT L 2
Variable depletion layer model
ID
n C oxW L W 2 n 3 L
(VGS V FB 2 F
2 s qN a ((2 F V DB ) 3 2 (2 F V SB ) 3 2 )
V DS , sat VGS V FB 2 F
g m, sat n* C ox
V DS )V DS 2
qN a s
W (VGS VT ) L
2 C ox
{ 1 2
2 C ox (VGB V FB ) 1} qN a s
1 n* n 1 2 2(2 F V SB )C ox 1 qN a s
A16-13
7.4. Threshold voltage VT ( (2 F VSB ) 2 F )
7.7. Advanced MOSFET issues V VT ) I D exp( G Vt
surface E 1 / 3
A16-14
2 s qN a C ox