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W. Y. Choi, B.-G. Park, and J. D. Lee, Fundamentals of Silicon IC Processes

I.

II.

III.

IV.

1


I. (CVD)

1. gas gas gas substrate gas

1) gas (1) thermal deposition (2) plasma deposition (3) photo (laser, UV) deposition

2) (1) APCVD (2) LTCVD (3) LPCVD (4) PECVD (5) PCVD

2


3) (1) , , .

(2) poly-silicon, Si3N4, SiO2 .

(3) Si3N4, SiO2 epilayer LTCVD

4) (1) (, ) (2) (3)

.

3


APCVD

Thin Film Reaction Gas (carrier) Temperature () Growth Rate

(nm/min) Throughput (wafer/hr)

Epitaxial Si

SiCl4 (H2)/H2

SiHCl3 (H2)/H2 SiH2Cl2 (H2)/H2

SiH4 (H2)/H2

1125~1120 1100~1150 1050~1100 1000~1075

500~1500 500~1500 500~1000 100~300

-

Poly Si SiH4 (H2) 850~1000 100 40

Si3N4 SiH4 /NH3 (H2) 900~1000 20 40

SiO2 SiH4 /O2 (H2) 200~500 100 160

4


LPCVD

Thin Film Reaction Gas (carrier) Temperature () Growth Rate


Epitaxial Si SiH2Cl2 (H2)/H2 1000~1075 100 - Poly Si 100% SiH4 (0.2 torr) 620 100 100

Si3N4

23% SiH4 (H2) (0.1 torr)

SiH2Cl2 /NH3 (0.3 torr)

640

800

19

4

150

100

SiO2

SiH2Cl2 /N2O

900 8 -

SiO2 SiH4 /O2

SiH4 /PH3 /O2 (0.7 torr)

450 450

10 12

100 50

5


PECVD

Thin Film Reaction Gas (carrier) Temperature () Growth rate


Si3N4 SiH4/NH3(N2)

(0.3 torr) 300 10 -

SiO2

SiH2Cl2 /N2O

250 84 -

a-Si SiH4 /H3 (0.1 torr)

300 6 -

6


2. CVD 1)

() (torr)

100~1200 0.1~760 , ,

, RF, , , 1 , W-Si, W-Mo 1 , WF3, MoF3

7

(1) APCVD LPCVD growth rate uniformity

(2) heating methods hot wall : electrical heating, IR Lamp cold wall : RF heating


2) LTCVD

.

(1) gas gas flow gas

(2) CVD (3)

/ SiH4/PH3

8


CVD

9


3) (photo CVD) (1) (Si3N4 : photo nitride) (2) defect (a-Si) (3) PCVD

10


(4)

2200 photon gas

Hg spectrum 2537 photon chamber 10 torr .

free radical .

.

243Hgh

34 H12NSiNH4SiH3 ++

HgHNHNHHg

HgHSiHSiHHgHgHgh

)P(Hg)S(Hgh

23*

34*

*

+++

+++

+

+

11


4) CVD

(1) LTCVD-NP: PSG, SiO2,BSG (700),

(3) LPCVD-LT: SiO2, PSG (700)

(5) PECVD-LT, LP: SixNyHz

(


1.

epitaxial arranged upon

1)

(1)

(2)

(3)

(4) defect

2) : 0.3~ 20

3) : 0.005~10 cm

II. (Silicon Epitaxy) 13


4) (1) (2) linear IC (3) bipolar (4) microwave (5) image sensor (6) CMOS IC

5) : , , autodoping, out-diffusion, , buried layer pattern 6) : , , , , , ,

, , , 7) : homo epitaxy hetero epitaxy

14


2. 1)

(1) 1960 .

(2) uniformity, repeatability autodoping .

(3) cylinder barrel type throughput (1), (2) .

15


2) LPCVD

(1) , .

(2) , .

(3) .

3)

(1)

SiC susceptor cold wall

(2)

.

16


17


3. 1)

(1)

(2)

(3)

(4)

(5)

(6)

18


2) SiH2Cl2 epitaxy

19


3) (1) Grove model:

20


(2)

)exp(

control transfer mass

controlreaction surface

)]([

)]([)1(

)(

0

1

1

11

2

1

/kTEKKYCC

/NhCV

/NKCV

NChK/hK

NFV

ChK/hKF/hK/CC

CKFCChF

aS

TG

GG

SG

GGSGS

GGSGS

GSGS

SS

SGG

==

+==

+=+=

==

21


5) (Grove ) (1)

: .

22


(2)

23


eGG

G

e

L

GG

RL

DDh

RL

ULLdxx

Lx

Uxx

Dh

23

32

32)(1)(

)(

0

==

===

=

(3)

: , :

U: , DG:

L: susceptor,

ULRe =

24


: 0 .

, , Re

Re hG

U L .

L CG .

susceptor 10~20.

eR

L32

=

GC

GC

(4)

25


4.

0.2~0.3

0.4~3.0

0.4~2.0

0.4~1.5

950~1.050

1,050~1,150

1,100~1,200

1,150~1,2500

()

< 2 SiH4=Si+2H2 , Pyrolysis

< 5 SiH2Cl2 +H2=Si+2HCl, Pyrolysis

SiH4

SiH2Cl2

5~10 SiHCl3+H2=Si+3HCl, Reduction

SiHCl3

5~10 SiCl4+2H2=Si+4HCl, Reduction

SiCl4

( )min/m

26


1) SiCl4 (1)

HCl dopant autodoping .

(2) .

(3) .

(4) .

(5) .

27


2) SiH4

(1) , ,

(2) HCl .

(3) .

3) SiH2Cl2

(1) SiH4~SiCl4

(2) 23 .

(3) SiH4 .

28


7. 1) : B2H6, PH3, AsH3

(1) SiH4 : 0.1 % of H2

(2) C = 5*1015 /cm3

(1 cm N-type)

(3) dopant

2)

SDG

ODGDD

CRF/CCDF

==

2

1 )(

29


3) : (1) : (2) :

) (

) (

SD

OD

CC

=

DG

GDSD /DRv

CC+

=

30


III. (LPCVD) 1. 1)

throughput . gas flow rate (H2 : 250 /min). RF .

2) throughput . gas flow rate . system .

3) LPCVD ( 3-2) torr 1000 . . wafer to wafer .

31


32


33


2.

R : , A : , Ea : ,

Pa, Pb, Pc Pn :

1)

2)

3)

4)

5)

nbaa PPPkTEAR )/exp(=

34


Si3N4 SiO2

SiH2Cl2, NH3 SiH2Cl2, N2O

() 750 900

0.7 ~ 1.5 % 1.0 ~ 1.6 %

1.0 ~ 1.6 % < 2 %

2.0 1.45

48% HF (/sec) 2.5~3.5 350~500

35


1)

36


2) wafer

37


3) , , SiO2

38


3. 1)

3

: 610

: 625

: 638

(a) 100 cc/min, 344 mHg

(b) 56 cc/min, 226 mHg

(c) 29 cc/min, 138 mHg

39


2) 600 , 600

40


41


4.

1)

SiH2Cl2 NH3 inlet outlet

42

: CVD Si3N4 SiO2

Si3N4 CVD SiO2 thermal SiO2

1.98 1.46 1.46 1.46

7.0 4.25 3.7 3.8

(g/cm3) 2.8 2.1 2.25 2.25


43

2) gas : SiH4, SiH2Cl2, CO2, N2O


44

: ,

:


IV. (PECVD)

1.

1)

hot plasma : arc discharge

cold plasma : low pressure glow discharge

PECVD

2)

(300 )

.

stoichiometry .

uniformity .

45


2. PECVD glow

1)

RF plasma

46

)/log(2 ie

efp mTMTe

kTVV =

e : , m : , Te : M : , Ti : , Vf : floating potential

** ion sheath (dark space) : ion


ion sheath

47


2) (radical)

SiH4 + N2O N2O SiH4 + CO2

CO2 SiO2 . Si-rich SiO2 . SiH4 + N2O SiO2

.

3) , ,

OCOmole/kcal127COONmole/kcal40ON

eXReRX

2

22

++++

+++

NONmole/kcal115ON2 ++

48


3. 1) : 50 kHz13.56 MHz matching 2) : 0.15 torr,

49


4.

1)

gas : SiH4 + NH3, SiH4 + N2 : 277(N-N), 110(H-NH2), 90(H-NH)

79(H-N) kcal/mole

: , , , , ,

grain , stress strain

, gas , gas flow rate, ,

,

50


51


52


53


2)

gas : SiH4 N2O, O2 CO2 40(O-N2), 119(O-O), 127(O-CO) kcal/mole

:

1) -

2) passivation layer

3) low capacitance

54


55

Slide Number 1Slide Number 2Slide Number 3Slide Number 4Slide Number 5Slide Number 6Slide Number 7Slide Number 8Slide Number 9Slide Number 10Slide Number 11Slide Number 12Slide Number 13Slide Number 14Slide Number 15Slide Number 16Slide Number 17Slide Number 18Slide Number 19Slide Number 20Slide Number 21Slide Number 22Slide Number 23Slide Number 24Slide Number 25Slide Number 26Slide Number 27Slide Number 28Slide Number 29Slide Number 30 III. (LPCVD)Slide Number 32Slide Number 33Slide Number 34Slide Number 35Slide Number 36Slide Number 37Slide Number 38Slide Number 39Slide Number 40Slide Number 41Slide Number 42Slide Number 43Slide Number 44IV. (PECVD)Slide Number 46Slide Number 47Slide Number 48Slide Number 49Slide Number 50Slide Number 51Slide Number 52Slide Number 53Slide Number 54Slide Number 55

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