Development and Application of Atomic Layer
Deposition
Chung-Ting Ko, Miin-Jang Chen
(atomic layer deposition, ALD)
(ultrathin film) ALD
12 (fin field-effect
transistor, FinFET) ALD
ALD ALD
ALD (nanoplasmonics)
Atomic layer deposition (ALD) is one of the most important semiconductor processes for deposition of nanoscale
ultrathin films. ALD offers many benefits, including precise thickness control with monolayer accuracy, high
uniformity over a large area, and excellent step coverage (conformality) on nonplanar high-aspect-ratio structures.
Hence ALD plays the important role in 300 mm silicon manufacturing technology and fin field-effect transistors
(FinFET). This article will introduce the principle of the ALD technique. Based on many years of experience in
the ALD technique, the key factors such as the ALD mechanism and the design of the ALD equipment which
have significant impact on the thin film deposition will be discussed. In addition, we also describe the increasingly
important ALD metal processes, and share the experience in the ALD processes of platinum and silver. Finally, the
application of ALD on the nanoplasmonics will also be introduced in this article.
ALD 2007
(atomic layer deposition, ALD) Intel ALD (HfO2)
1970 1977 45 nm
Tuomo Suntola ALD ALD
(1) (2)
1983 1998 ALD
ALD
(3)
1990 ALD
38 198 103.3
ALD GPC (growth per cycle)
(conformality) GPC 0.05 0.1 nm
(chemical vapor deposition, CVD)
(physical vapor deposition, PVD) ALD
1 ALD
(precursor)
(half cycle) ALD
(chemisorption)
ALD (ALD ALD
cycle) (monolayer) (
)
(layer-by-layer) ALD
(self-limiting reaction) ALD
ALD (ALD window)
ALD cycle
CVD
ALD
1st half-cycle
Starting surface Precursor adsorption After purge step
2nd half-cycle
LD
a lA
erm
Th
Reactant exposure
Starting surface Pla After purge step
as
sis sma
ted -
AL
D
1.
ALD
(2)
Plasma exposure
198 103.3 39
(5)
ALD cycle 3
ALD ALD
Al(CH3)3
Al(CH3)3 OH
Al(CH3)3
CH4
CH4
ALD (thermal ALD
mode) (plasma mode) 1
(2)
ALD
ALD
Al2O3 ZnO TiO2 ZrO2 HfO2 TiN CH4
A l 2O 3 ALD
(4)
ALD cycle Al2O3
ALD Al 2 O 3 ALD GPC 0.11 0.12 nm
(Al(CH 3 ) 3 , Al(CH3)3
trimethylaluminum, TMA)
150 200 °C
Al2O3 ALD
2Al(CH3)3 + 3H2O Al2O3 + 6CH4 (step coverage)
H = 376 kcal Al2O3 ALD
ALD
2 Al(CH 3) 3 (1) (2) (3)
OH CH4 (4) (5)
Step-by-Step with Monolayer Accuracy
TMA Introducing Water Introducing 1 Cycle Deposition
Al(CH3)3 H 2O
Self-limiting reaction
CH3 CH3 O Sequential reaction (Gas)
Precise thickness control
Al O H H
Uniformity
H H Conformality
CH3 CH3 CH3 O
H H
Al H H
CH4
CH3 CH3 CH3 CH3 O O
CH3 O
CH4
H H Al Al Al Al
Monolayer
O O O O O O
2.
Al2O3 ALD
Substrate Substrate Substrate
40 198 103.3
Al-OH*
0 Al(CH3)3
TS
10
E (Kcal/mol)
20
Al-(CH3)2
30
Al(CH3)3(a) 3.
40
CH4 Al2O3 ALD
(7)
(6)
Al2O3 (radicals)
ALD ALD
OH Al(CH3)3
Al2O3 ALD ALD
(6)
Al2O3
ALD
(7, 8)
ALD
(9, 10)
( ) TiCl4 (TaCl5)
ALD 250 400 °C
Ti* + TiCl4 TiTiCl4* (Ta* + TaCl5 TaTaCl5*)
TiCl4* + 4H+
CVD Ti* + 4HCl (TaCl5* + 5H+ Ta* + 5HCl)
ALD TiCl 4 (TaCl 5)
Cl
198 103.3 41
ALD (2)
GPC 0.15 0.17 nm ALD ALD
GPC 0.167 nm
ALD
(9)
ALD 1 40 PV = nRT (n) (T)
(P) (V)
28 nm 11
nm ALD
ALD
ALD
Al2O3 ALD
(4)
ALD
ALD ALD
ALD
CVD PVD
ALD
ALD
CVD
ALD
ALD
ALD
ALD ALD
ALD (inductively-
coupled plasma, ICP) (capacitively-
CVD coupled plasma, CCP) ICP CCP
ALD (remote
ALD ALD plasma) (direct plasma) ALD
(2)
(1) 4 ICP
42 198 103.3
ALD 155 ° C
CVD ALD
CCP
ALD T. Aaltonen
(12)
CH 3C 5H 4Pt(CH) 3
ALD CH3C5H4Pt(CH)3
300 °C
ALD 300 °C ALD
CH3C5H4Pt(CH)3
ALD
(12)
Pt-Ox
ALD Pt(s) + O2(g) Pt Ox
Pt Ox + CH3C5H4Pt(CH)3
Pt(s) + CO2(g) + H2O(g) + other byproducts
ALD
ALD
(13-15)
530
°C
(16)
ALD 330
ALD M. Utriainen °C (desorption)
(11) (17)
Pt(acac) 2 ALD GPC 0.045 nm
Pt(acac) 2
Plasma gas
Dielectric tube Plasma gas &
with coil Precursors
Electrode
with
Precursors
showerhead
Mesh
4.
ALD (a)
Pump
Pump (b)
(a) (b)
(3)
198 103.3 43
(18)
(
ALD 1/10)
(24)
5
ALD M.
(19)
Karinieni 2011
Ag(fod)(PEt3) LSPR
120 140 °C GPC 0.03 nm Ag(fod) M
(PEt3) ALD m
(20-23)
LSPR
230 °C ALD M = 2 m M m
Ag(fod)(PEt3) LSPR
(25)
ALD
LSPR
Purcell
(26)
photonic
(27)
plasmonic density of states
(28, 29)
ALD
LSPR
ALD
(layer-by-layer)
ALD
ALD
ALD
(nanoplasmonics) (localized
surface plasmon resonance, LSPR)
Light Light
5. ERES
E
E
(22)
44 198 103.3
Distance
2 nm ZnO Quantum Well
Normalized PL Intensity
10 nm ZnO Thin Film
ZnO Emitter
Al2O3 Spacer Optimized Distance
15 nm
105
PL Enhancement Factor
Al2O3 Layer
300 350 400 450 500
6.
Wavelength (nm)
Silicon Substrate ALD
LSPR
ZnO
2 nm ZnO
Hight uniformity up to 4" Substrate
(30)
LSPR 10.2 nm Al2O3 10.6 nm
15.1 nm Al2O3 5.4 nm ZnO
ALD ALD
LSPR ZnO
2 nm ZnO Al2O3
6 ALD ZnO
4 ZnO
6
Al2O3 (nanostructured Pt, ZnO 15 nm
nano-Pt) Al2O3 ZnO ZnO (105 )
Al2O3 ZnO ZnO
ALD 15 nm ZnO
ZnO 2 nm LSPR
LSPR 2 nm ZnO
6 10 nm ZnO
(transmission electron 380 nm
microscopy, TEM) ALD 2 nm ZnO
7 360 nm
ALD ALD LSPR
10 nm Al2O3 10 nm 15
(30)
nm Al2O3 5 nm ZnO TEM
198 103.3 45
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(2013). in electro-optical engineering from
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National Taiwan University. He is currently a professor in
Technol B, 20, 1321 (2002).
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B, 18, 2016 (2000). National Taiwan University.
46 198 103.3
