68

7.

7.1

IC

7-1, 7-2

DRAM, IC

7-3

(a)

SiO2

(b), (c)

SiO2

2

(b)

SiO2

SiO2 (c)

DRAM

W Etch Back

Deep Contact

Hole Etch

Self Aligned Contact

Hole Etch

Via Hole Etch

LDD Spacer Etch

SiN Mask Etch

256MDRA \ A Gb Ov Z X

Al Etch

Gate Etch

Cover Etch

DRAM

W Etch Back

Deep Contact

Hole Etch

Self Aligned Contact

Hole Etch

Via Hole Etch

LDD Spacer Etch

SiN Mask Etch

256MDRA \ A Gb Ov Z X

Al Etch

Gate Etch

DRAM

W Etch Back

Deep Contact

Hole Etch

Self Aligned Contact

Hole Etch

Via Hole Etch

LDD Spacer Etch

SiN Mask Etch

256MDRA \ A Gb Ov Z X

Al Etch

Gate Etch

DRAMDRAM

W Etch Back

Deep Contact

Hole Etch

Self Aligned Contact

Hole Etch

Via Hole Etch

LDD Spacer Etch

SiN Mask Etch

256MDRA \ A Gb Ov Z X

Al Etch

Gate Etch

Cover Etch

7-1 DRAM MOS

0.13 m

Dual Damascene

Etch

LDD Spacer Etch

SiN Mask Etch

Cover Etch

Gate Etch

Al Etch

7-2 IC MOS

69

SiO2

(b)

(c)

5

()

[]

7-4

7-5

3

1 25 5

7-3 Si SiO2 (a)

(b)(c)

7-4 R

R = T/ t

70

7-5

(a)

(b) 9 () 21 ()

7-6 ()

()(a), (b)

[]

7-6

()

(

)

7-7 0.5m

4m~0.5m (

)

71

7-8

(a)

(b)

7-9

7-7

[] [2 ] [3 ]

[4 ] 4~0.5m , 0.5m

72

[]

Ro, Rs, Rm

()Ss, Sm

Ss = Ro / Rs (7.1)

Sm = Ro / Rm (7.2)

25:1 ~ 50:1 7-8

(a)

(b)

[]

7-9

7.2

(1)

7-10 3

7-11

Si, Al

73

(1)

(2)

(3)

7-10

7-11

(2)

1970

7-12

(3)Si

Si Si HNO3 + HF (

) Si

Si + HNO3 + H2O SiO2 + HNO2 + H2 (7.3)

SiO2 + 6HF H2SiF6(SB) + 2H2O (7.4)

7-12

(a), (b),(c)

74

7-13 Si

KOH(23.4wt%) + IPA(13.3wt%) +

H2O(63wt%) SiO2

80Si(100)

0.60m/min

Si(111) 0.006

m/min

SiO2

(4)SiO2

Si (SiO2) HF()

Si HF

SiO2 +6HF H2SiF6(SB) + 2H2O (7.5)

49%HF() 25 300/sec

[NH4F(40%) + HF(49%), 6:1] 25

20/min

(5)Si-N

Si3N4

N

Si-N

Si3N4

H3PO4() 80

SiO2

7-14 Si3N4

7-13 Si

()

()

7-14 Si3N4

75

7-15, 7-16 Si3N4

Si3N4 SiO2

Si3N4 SiO2 SiO2

IC Si3N4 Si

7-15 Si3N4

7-16 Si3N4

14 7

76

SiO2 Si3N4 SiO2

SiO2

14 7

Si3N4

(6)Al

Al Al-Si, Al-Si-Cu

1~2% Al

80%H3PO4() + 5%HNO3() + 5%CH3COOH() + 10%H2O

35~45 Al H2

7.3

(1)

7-17

RF

7-17

77

7-18

3

RIE

RF()

2

2

RF

7-19 3

()

RIBE(reacitive ion beam etching)

RIBE

RIE

RIE

MERIE

0.1

1.0

10

100

1000

e

V

7-19

7-18 (RIE )

78

RIE (reactibe ion etching

) RIE RIE

MERIE (magnetic-enhaced RIE)

RIE

RIE ~

~ 7-20, 7-21 7-17, 7-18

1

2

3 45

6

7

8

7-20 RIE ~

79

7-22, 7-23 RIE 7-22 Si

Ar

10 Si

7-22

Si ()XeF

()Ar XeF

()Ar

+

+ +

+

+

7-23

()

CF4

()SiF4, CO

CF4 + e- CF3 + F

CF4 + e- CF3

++ F + e

CF3 () CF3 ()

F () F ()

CF3 CF2 + F

Si

CF3 () CF3 ()

F () F ()

Si + 4F SiF4

CFn + CxFy CuFv ()

()

1

2

3

4

5

6 6 7

8

7-21 CF4-Si RIE ~

7-21 CF4-Si RIE ~

80

CF4 7-23

RIE

()

RIE ~

7-1

7-1 RIE

(a) ()

(b)

(c)

(d)

(e)

(f)

(g)

(h)()

(2)

IC

A ~D 4

7-24

A

B ()

()

C

D

81

7-24

7-2

82

7-2

RIE

(3)Si

Si, SiO2

CF4, CF4 + O2, CF4 + H2 3

Si

CF4 F

Si

1

Si F

SiF4

7-25

7-26 CF4 + O2

O2

Si SiO2

F

O2

20~30%

F

B

C

A

D

7-25 Si F

A Si + F SiF, B SiF + F SiF2, C Si + F SiF3, D

SiF3 + F SiF4(V), V: vapor phase()

7-26 Si, SiO2 CF4 + O2

O2 (%) Si() SiO2()

83

CF4 SiO2

Si Si 7-25

SiO2 + C Si-O + CO(V) (7.6)

Si-O + C Si- + CO(V) (7.7)

Si- + F SiF (7.8)

SiF + F SiF2 (7.9)

SiF2 + F SiF3 (7.10)

SiF3 + F SiF4 (7.11)

SiO2

CF4 + H2 Si SiO2

Si

F + H HF (7.12)

n(CFx) (CFx)n [S] (7.13)

SiO2

CFx + O CO(V) + xF(V) (7.14)

SiO2 + C Si-O + CO(V) (7.6)

Si-O + C Si- + CO(V) (7.7)

Si- + F SiF (7.8)

SiF + F SiF2 (7.9)

SiF2 + F SiF3 (7.10)

SiF3 + F SiF4 (7.11)

n(CFx) (CFx)n [S] (7.13)

(7.12) F Si

(scavenge)(7.7)~(7.11) Si

H2 (7.13) Si

7-3Si

7-27 Si, SiO2,

CF4 + H2 H2 (%)

84

(4)

7-4

Si

Al Al Al

Cl Al

AlCl3

Al + 3Cl AlCl3(V) (7.15)

Al

AlCl3

Al AlCl3

2AlCl3 + 3H2O 6HCl + Al2O3, 2Al + 6HCl

2AlCl3 + 3H2 (7.16)

AlCl3

O2

(5)

[]

7-19 3 7-29,

7-30, 7-31

7-3 Si

E

(kcal/mol)

C-O Si-O Si-F Si-N Si-Cl Si-Si Si-Br

E 257 192 130 105 77 76 70

7-4

SiO2 CF4, CHF3, C4F8

Si3N4 CF4 + O2, SF6

poly-Si, WSi Cl2 + HBr, SF6

Al, Al+Si(1~2%), Al+ Cu(1~2%) Cl2+BCl3,Cl2+CCl4

W SF6

O2

7-28 Al

85

RIE

+

+

+

+

+

+

+

+

+

+

+

7-29

()

7-30

()

RF

RIE

RIE

1 RF

RIE

(electron-cyclotron

resonance, ECR)

(inductive-coupled plasma, ICP)(helicon-wave plasma)

(surface-wave plasma)

13.56MHz

13.56MHz

7-31 RIE

()

86

[]

6

IC

7-32 RIE 7-33 RIE

7-32 RIE

4~5 10

7-33 RIE

87

[]

He

7-34, 7-35

He

He

He

7-34

7-35

7.4

(1)

5000 SiO2 30

2,400

(2)

(3) 4

(a)Si, (b)SiO2, (c)Si3N4, (d)Al.

(4)

88

(5) 6000 SiO2 HF 750/min

SiO2 10%

SiO2

SiO2

(6) Si3N4

(7) 1 m IC

(8)

(9)

2

(10)

IC

(11)

(12)

(RIE)

(13) 1

(a) Si

(b) SiO2 Si

(c) Al

(14) Si

SiO2

(15) Al

(16) RIE

(17)

(18)

89

(19)

(20) He