Upload
others
View
1
Download
0
Embed Size (px)
Citation preview
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
GaN/Si LED and HEMTs
Speaker : Rong Xuan
Industrial Technology Research Institute (ITRI)
Electronics and Optoelectronics Research Lab
Opto-electronics Device &System Application Division
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Outline
Introduction
GaN/Si LED Technology
GaN/Si HEMTs Technology
Conclusions
2
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
``
Epiwafer providers
TDI Hitachi Cable NTT Kyma OptoGaN AZZURRO
CREE TDI Hitachi Cable NTT
CREE Hitachi Cable NTT Toyoda Gosei AZZURRO IQE,Kopin Picogiga
Sumitomo SEI Kyma LumiLOG Samsung-corning Hitachi Cable AZZURRO
Nitronex AZZURRO Picogiga IMEC IQE NTT DOWA
Toshiba Ceramic (TOCERA)
BlueGlass
Device maker Lumileds Osram Nichia Toyoda Gosei Velox
CREE Osram
CREE Fujistu RFMD NXP Freescale NEC, TriQuint
Sony Nichia NEC Toyota
Nitronex OKI TriQUINT MicroGaN, ST, IR, Sanken,Fuji GaN system
R&D R&D
Application Blue/white LED, power devices
Blue/white LED
RF devices Blue/violet laser diode, power devices
Power devices ,RF,LED
RF devices Power devices
Blue/white LED
GaN
Sapphire
GaN
n SiC
GaN
S.I. SiC
GaN
Bulk-GaN
GaN
Silicon
GaN
3C SiC GaN
Glass Silicon
Ref.:Website of Yole
Substrates for GaN Epitaxy
GaN template Vendors or Products
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
4
Why GaN on Si ?
Prospects:
1) Large area and highly qualified wafer available
2) Sophisticated silicon technology available
Micro-machining, Fine lithography
3) Integrated opto-electronic devices possible (Si-photonics)
Difficulties:
1) Large lattice mismatch and different lattice structure
Poor hetero-interface, High density defects
2) Large difference of thermal expansion coefficients
Cracking, Bowing
3) Strong reaction between GaN and Si
Ga and Si meltback etching reaction
How to resolve:
1) Insertion of AlN and/or multilayered buffer layer
2) Selective Area Epitaxy
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
6”~8” GaN/Si 有效使用面積
1. Investment
♦ Capacity
A = n••r2
A(4“)/A(2“) = 1
=> same capacity
♦ with 3mm edge exclusion
A = n••(r-e)2
A(4“)/A(2“) = 1.14
=> +14% capacity
♦ System investment
$/1.14 = 0.88
=> 88%
56x2” 14x4” 56x2” 8x6” 56x2” 5x8”
1. Investment
♦ Capacity
A = n••r2
A(6“)/A(2“) = 1.29
=> +29% capacity
♦ with 3mm edge exclusion
A = n••(r-e)2
A(6“)/A(2“) = 1.53
=> +53% capacity
♦ System investment
$/1.53 = 0.65
=> 65%
1. Investment
♦ Capacity
A = n••r2
A(8“)/A(2“) = 1.43
=> +43% capacity
♦ with 3mm edge exclusion
A = n••(r-e)2
A(8“)/A(2“) = 1.74
=> +74% capacity
♦ System investment
$/1.74 = 0.58
=> 58%
2. Running Cost
$/1.14 => 88%
3. Chip Process
Assume 150% processing time of
4“ compared to 2“:
(42/1.5)/(22/1) = 2.7x Throughput
2. Running Cost
$/1.53 => 65%
3. Chip Process
Assume 200% processing time of
6“ compared to 2“:
(62/2)/(22/1) = 4.5x Throughput
2. Running Cost
$/1.74 => 58%
3. Chip Process
Assume 250% processing time of
8“ compared to 2“:
(82/2.5)/(22/1) = 6.4x Throughput
Ref.:Aixtron
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Si (111)
AlN
buffer
un-doped GaN
n-doped GaN
MQWs
p-doped GaN
Full LED
coincidence
n-GaN quality
(002)/(102) of X-ray
350/450 arcsec
n-GaN thickness
> 3 μm
Difference and coincidence for GaN/Si LED & HEMTs
u-GaN thickness > 5 μm
u-GaN quality
(002)/(102) of X-ray
600/1200 arcsec
Issue : quality & n-GaN thickness
Si (111)
AlN
buffer
un-doped GaN
AlGaN (2DEG)
Power device
Issue : u-GaN thickness
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Material Thermal
conductivity
(W/cmK)
Thermal ex-
pansion coef-
ficient in-plane
(10-6/K)
Lattice
mismatch
GaN/substrate
(%)
a(Å ) c(Å ) Thermal
mismatch
GaN/substrate
(%)
GaN 3.189 5.189 1.3 5.59 _ _
AlN 3.11 4.98 2.85 4.2 2.4 25
(111)Si 5.431 _
1-1.5 2.59 -16.9 54
Sapphire 4.758 12.991 0.5 7.5 -16 -34
A. Dadgar et al., phys. stat. sol. (c) No. 6, 1583– 1606 (2003)
6H-SiC 3.080 15.12 3.0-3.8 4.2 3.5 25
Challenges of GaN/Si Epitaxy
7
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
8
In-Situ curvature measurement system
Reasons for wafer curvatures
1.Vertical temperature gradient :
2. Lattice mismatch :
3. Thermal stress
0
200
400
600
800
1000
1200
1400
-100
-50
0
50
100
150
200
0 1 104
2 104
3 104
T
curvature middle
Time (s)
Gro
wth
te
mp
era
ture
(C̊
)
Curv
atu
re (1
/km
)
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
9
6 inch GaN on Si
Si
AlN
SL03
AIX CRIUS I MOCVD
GaN template on Si Substrate
SL01
SL02
GaN
LED structure
same as on
sapphire
-150
-100
-50
0
50
100
150
0 5000 1 104
1.5 104
2 104
Process time (s)
Curv
atu
re (
1/K
m-1
)
50X
50X
GaN on Si without island structure
GaN on Si with island structure
In-situ curvature meansurement & top view of OM pictures
Crack surface
Crack free
-150
-100
-50
0
50
100
150
0 5000 1 104
1.5 104
2 104
Process time (s)
Curv
atu
re (
1/K
m-1
)
50X
50X
GaN on Si without island structure
GaN on Si with island structure
In-situ curvature meansurement & top view of OM pictures
Crack surface
Crack free
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
10
Base on Aixtron Crius 1 Supporting
Insitu monitor is needed for GaN/Si epitaxy
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
GaN/Si LED Technology
11
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Issues of GaN LED on Si substrate
1. Wafer bow & Epi-file crack
2. Epitaxy quality of GaN layer
3. Surface morphology of GaN template
4. Luminescence property (IQE)of active region
5. Electrical property of GaN LED on Si substrate
6. Reliability
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
GaN/Si Stress Engineering Solutions
Crack surface of GaN/Si
Crack and pits free of GaN/Si
Si substrate
A: Selective area growth
1.Pattern Sub.
2. Rod growth(ITRI’s patents)
3. Elog
4. porous Si substrates or
B: Strain release on blank Sub.
Nucleation 1. Al pre-deposition
Compositional
graded layer
1. AlGaN linear or step graded layer
2. AlGaN/GaN SLs
3. InAlGaN quarternary graded layer
Inter-layer
1. LT-AlN
2. SixNx
3. LT-GaN nucleation
13
Aixtron Crius 1
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
TMAl pre-deposition 20 sec .
1100oC
Temp
time
AlN
N.L. AlGaN / GaN
TMA pre-deposition for GaN/Si Growth
NH3
TMAl
TMGa
1000 sccm
2500 sccm
20 sccm
20 sccm
Reactor : AIX 2000
H2固定15000sccm
1. Prevent SixNy formation
2. Prevent meltback etching reaction between Ga and Si
14
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
15
AlN nucleation
AlGaN SLs
In-Situ SiN mask
n+GaN
n+GaN
n+GaN
p-GaN/MQW
AlN/AlGaN interlayer
AlN/AlGaN interlayer
Single SiN layer Double SiN layer
In-Situ SiN mask
In-Situ SiN mask
3.3 um AlGaN
1.7 um n-GaN
By using in-situ SiNx layer can suppress the dislocation punch through active region
TEM cross-section image of GaN/Si epitaxy
Aixtron Crius 1
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
GaN template quality on 6 inch Si Sub.
0.0 0.4 0.8 1.2 1.6 2.00
200
400
600
800
1000
1200
1400
1600
1800
2000
X-r
ay F
WH
M o
f (1
02
) (a
rcse
c)
GaN thickness (m)
AlGaN buffer 3.3um
AlGaN buffer 2.5um
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
17
1. Quality調整 :
002 = 395 arcsec 102 = 466 arcsec
OM : 20X
RMS = 0.226 nm
=> Quality is almost the same with that on Al2O3.
PS : world record is 350 for (002) and 430 for (102)
2. n-GaN growth :
4.2 μm including
2.5 μm n-GaN n-GaN 2.5 um
(~2.5E18 cm-3)
GaN/Si LED testing
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
18
Relationship between Epi-thickness & wafer bow
-150
-100
-50
0
50
100
0 5000 1 104
1.5 104
2 104
Growth time (s)
Cu
rvatu
re (
km
-1)
650 um thick substrate
0
0.05
0.1
0.15
0.2
0.25
0.3
0 5000 1 104
1.5 104
2 104
Growth time (s)
Re
fle
cta
nce
(a
. u
. )
650 nm light source
Sample A epi-thickness 2.2 um
Sample B epi-thickness 2.7 um
Sample C epi-thickness 3.6 um
Reflectance of sample C
It can be calculated the curvature
change about 51 km -1 /um(epi-
growth) during the cooling down
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
19
In-situ reflection & curvature measurement
6inch-SL-20 LED 03
6inch-SL-22 LED 04
6inch-SL-22 LED 05
6inch-SL-22 LED 06
0
500
1000
1500
2000
2500
3000
3500
4000
350 400 450 500 550
Wavelength (nm)
EL
in
ten
sit
y
6inch-SL-20 LED 03
6inch-SL-22 LED 03
6inch-SL-22 LED 04 (SiNx)
6inch-SL-22 LED 06 (SiNx)
In-situ curvature
Less compress stress
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
RMS and topography 3D profile
AFM inspection result
Area RMS ~0.226nm
Avg. Height ~1.746nm
6”GaN/Si LED testing (1)
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
21
6”GaN/Si LED testing (2)
0
1000
2000
3000
4000
5000
8.55 104
8.65 104
8.75 104
8.85 104
position (arcsec)
X-r
ay
co
un
ts (
a.
u.)
(102)
FWHM ~ 430 arcsec
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
22
0
500
1000
1500
2000
2500
3000
3500
4000
350 400 450 500 550
Wavelength (nm)
EL in
ten
sity (
a. u
.)
EL test & device process
LED on sapphire
FWHM ~ 19 nm
LED on Si (SL-
18-LED01)
FWHM ~21 nm
OM picture of LED on Si (after ITO & mesa etch )
6 inch-SL-18-LED 01
6”GaN/Si LED testing (3)
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
23
I-V test data on thin GaNLEDs
Sample ID Vf1
(20mA)
Wdd
(20mA)
Wpd
(20mA)
HWFM
(20mA)
Po1 mW
(20mA)
Vf2
(100 mA)
Po2
mW(100mA)
Ir -5V
(uA)
Normal sapphire
with mirror coating
at back side 3.089 455.35 448.56 19.6 6.91 3.738 28.14 0.0035
6inch-Si LED
Before Si removed 2.968 459.02 454.55 19.1 2.0003 3.649 8.8998 0.003
6inch-Si LED
after Si removed 2.932 456.4 451.3 18.6 7.05 3.59 28.93 0.005
Х 3.5 after Si removed
Light out put power increased by 3.5 times at 20 mA current
injection after Si substrate remove.
COW test
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
24
GaN/Si HEMTs Technology
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Fuji Electric Scenario for Application of WBG Device
Source: Fuji 2010 25
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
26
Main Applications Accessible to WBG
Specs/market data of today silicon devices
Power Supplies/
PFCUPS HEV Solar panel Wind turbine
Industry
Motor
Drive
Energy
Transport.
Grid, Rail
Main DevicesMOSFET
Diodes
MOSFET
IGBT
Diodes
MOSFET
IGBT
Diodes
IGBT
Diodes
IGBT
Diodes
IGBT
Diodes
GTO, Thyristor
IGBT, PiN Diode
Breakdown
Voltage (V)600V 600/1200V
650V→ 900V
>1.2kv
600V (90%)
1200V (10%)
Today 690V
Trend: 3 -4 KV600V to 1200V > 5KV
Peak current (A)
(for a single chip)0.5 - 10A 2 -100A 50-200A 75A 150A 3 - 100A 10 - 200 A
2008 volume (Munits)MOS: 1600
Diode:1600
IGBT:800
Diode: 800
IGBT:2.6
Diode: 2.6
IGBT:12
Diode: 12
IGBT:0.11
Diode: 0.11
IGBT:25
Diode: 25
wide reange of
specs/prices
2008 ASP for a
discrete device
Tr: $0.6 - $1
Diode: $0.3
Tr: $1.2
Diode: $0.6
Tr: $9
Diode: $5
Tr: $8
Diode: $4
Tr: $20
Diode: $8
Tr: $8
Diode: $4
wide reange of
specs/prices
2008 Si device
market ($M)
(discrete)
1800 1400 ~ 40 150 < 3 ~300 ~110
Source: Yole Development
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
27
Power Devices Vendors or Products
Source: Gartner, Yano Research: IEK/ITRI (2010/10)
Power Devices Vendors and Products (1/2)
Toshiba
STMicroelectronics
Infineon
Fairchild
Vishay
Mitsubishi Electric
International Rectifier (IR)
ON Semiconductor
Fuji Electric
NEC Electronics
Shindengen Electric
Rohm
Renesas Technology
Panasonic
Microsemi
NXP
Sanken
Hitachi
Diodes
Toyota
3C 工業/航太/醫療/軍用 車用3C,家電用 工業,醫療,航太,軍用 車用
Source: Gartner; Yano Research; IEK/ITRI (2010/10)
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Comparison of Si / SiC / GaN
Breakdown
Electric Field
(MV/cm)
1
3
5
Thermal
Conductivity
(W/cm °C)
Melting Point
(°C)
Saturation Electron
Velocity ( x107 cm/s)
Energy Gap
(eV)
1K
3K
5K
1
3
5
1
3 5
1
3
5 Si
SiC
GaN
Low Loss: x100
High Voltage: x10 Numbers Compared
between SiC & Si
Radiation: x3
High Frequency: x10
High Temperature: x3
Endurable for Radioactivity: x3
Blue LED Substrate
Automobile Parts
Heating Elements
Structural Materials
…
Power Devices
for Invertors / Converters
in EV/HEV, Renewable
Energy Systems
(PV, Wind Turbid,…)
RF & Microwave
Components
Source: IEK/ITRI (2010/07)
-- Characteristics and Applications
28
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Breakdown Voltage of Different Epi-structure (1)
29
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
2-20um 2-30um
Ron(mΩ-cm2)@Vg=0V 13.90 15.58
Breakdown Voltage
(V)@100uA 855 863
Vth(V) -2 -2
gm (mS/mm) 55 62
Ids (mA/mm) @Vg=1V 160 156
GaN/Si HEMTs Device Performance
30
0 100 200 300 400 500 600 700 800 900 100010
-5
10-4
10-3
10-2
10-1
100
Breakdown Voltage
Ids (
mA
/mm
)
Vds (V)
without C-doped
C-doped
Vgs=-5V
Thickness: 3.9 μm
Mobility: 1100 (cm2/Vs)
Concen.: -1.41E13 cm-2
Rsh: 400 (ohm/sq)
XRD: (002)/(102) = (539.4)/(1078)
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Surfa
ce state
s
AlGaN Barrier Layer Structure
31
R.J. Trew. In: Int. Semicond. Dev. Res. Symp. (Dec. 5–7,2001) p. 432.
Appl. Phys. Lett, vol. 85, pp. 6164-6166, 2004.
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
AlGaN Barrier Layer Growth on Si
單層的Al0.3Ga0.7N有較高的導通電流,雙層的Al0.38Ga0.62N/ Al0.24Ga0.66N barrier
layer則得到較高的Sheet Concentration與較低的導通電阻。
32
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
33
國際技術 Normally-off GaN HEMT Device
Recessed gate [Dry etch]
[ Sharp] MOS-HEMT [ Fujitsu] MIS-HEMT
•分析說明
-閘極蝕刻凹槽(gate trench)
GaN/oxide介面產生很多缺陷,
影響channel mobility
-蝕刻深度控制不易,造成
Threshold Voltage fluctuations
Without Recessed gate
[ Panasonic] P-AlGaN GATE [ Hong Kong University] F-ion HEMT
•分析說明
- 磊晶成長p-AlGaN可能造成
Doping原子擴散至2-DEG channel
- p-AlGaN濃度提昇不易,影響
Threshold Voltage
- 大電流操作下,F-ion HEMT可能有
reliability的問題
Vth(v) 5.2
Id (mA/mm) 200
Vbd(v) 400
Ron(mΩ-cm2) 2.6
Vth(v) 3
Id (mA/mm) 800
Vbd(v) 320
Ron(mΩ-cm2) ?
Vth(v) 1
Id (mA/mm) 200
Vbd(v) 800
Ron(mΩ-cm2) 2.6
Vth(v) 0.75
Id (mA/mm) 300
Vbd(v) ?
Ron(mΩ-cm2) ?
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Bottleneck of MIS HEMTs
SF6
Substrate
u-GaN:1.5um
U-Al0.25Ga0.75N; 20nm u-GaN:1nm
SiO2:300nm
u-GaN:1nm
SF6- 3/5/7min
- Ids與Vth的相關性
-2.0 -1.5 -1.0 -0.5 0.0 0.5
0
20
40
60
80
100
120
140
160
180
200
220
240
Vth (v)
Id (
mA
/mm
)
0
500
1000
1500
2000
2500
3000
VB
D (
v)
0 min.
3 min.
5 min.
7 min. △Vth=2 v
△Ids=-110mA/mm
34
臨界電壓從-1.8 V提升至+0.2 V,導通電流下降58%。
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
奈米膠
SiO2 mask 奈米壓印圖案
SiO2 pattern by RIE
Rod:
Pitch 750 nm
Fill factor 1:1
Nano-rod Fabrication
35
550umX550um
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
I-V Testing Results
利用nano rod製作在閘極區域下方,臨界電壓從-2 V提升至+2 V,導通電流下降34%。
可維持與D-mode HEMTs相同的崩潰電壓~860V 36
Vds=10V Vds=10V
Ioff=3.31mA/mm Ioff=0.02mA/mm
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Sample Resistivity
(Ω∙cm)
Carrier concentration
(cm-3)
Mobility
(cm2V-1sec-1)
NiO
(100% of O2) 6.1 x 10-2 2.23 x 1019 4
Characteristics of P+-NiOx coated by Sputter
glass Substrate
NiO film
(100 nm)
2’’ Target Power
(w)
Ar:O2 flow rate
(sccm)
temperature
NiO 80 0:16 RT
_Condition:
_Hall measurement:
NiOx Insulation layer
NiOX條件:
Ni(25nm)/O2(9sccm)/T(250℃)/RTP(N2/O2) 500℃ ,1min
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
HEMT Device (Nano-pattern P+-NiOx gate) -1
Recessed gate Recessed gate
(nano-pattern)
NiOx P+-NiOx NiOx P+-NiOx
Vth (V) - 0.6 2.3 0.2 2.2
△Id↓% 8.4 20 15.7 36
Vbd (V) 2236 2328 2335 1986
Ion/Ioff 3.5E7 3E7 6.1E6 1.5E8
S.S(mV/dec) 80.14 252 105.21 84
_ Overview
Si (111)
buffer
u-GaN
S D /SiNx/SiO2 u-AlGaN
G
NiOx layers
Si (111)
buffer
u-GaN
S
G
D
u-AlGaN
NiOx SiN/SiO2
Recessed gate Recessed gate (nano-pattern)
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
-4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 100
50
100
150
200
250
300
350
400
450 STD
Porous-450-MIS-P+-NiOx
Rods-750-MIS-P+-NiOx
Rods-800-MIS-P+-NiOx
DOWA-36 nano-pattern-MIS-P+-NiOx
Transfer I-V Characteristic of GaN HEMT
Vgs(V)
Id(m
A/m
m)
△Id:↓36%
-5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 100
5
10
15
20
25
30
35
40
45
50 STD
Porous-450-MIS-P+-NiOx
Rods-750-MIS-P+-NiOx
Rods-800-MIS-P+-NiOx
DOWA-36 nano-pattern-MIS-P+-NiOx
Transfer I-V Characteristic of GaN HEMT
Vgs(V)
Id(m
A/m
m)
△Vth:4.2V
•比較△Vth &△ Ids(max.)變化:
DOWA-36 Vth Id(max) △Vth △Id(max)
STD -2.0 418
Pitch 350 nm; Fill factor 1/1
MIS-Structure- P+-NiOx:100nm 2.2 266 4.2 36.4%
Pitch 750 nm; Fill factor 1/1
MIS-Structure- P+-NiOx:100nm 3.2 63 5.2 84.9%
Pitch 800 nm; Fill factor 5/3
MIS-Structure- P+-NiOx:100nm 3.2 8.6 5.2 97.9%
HEMT Device (Nanos-pattern P+-NiOx gate) -2
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Ids improvement
( AlGaN barrier structure)
BV improvement
( Carbon doped)
Normally-on
GaN HEMT Device
Ig leakage suppressed
( NiOx applied)
Normally-off
GaN HEMT Device Ids improvement
(Nano-pattern applied)
GaN/Si HEMTs Conclusions
40
GaN/Si epi quality improvement
(linear graded AlGaN buffer layer)
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Summary
• GaN/Si磊晶技術關鍵在應力控制,ITRI以nano Rod、
SixNyCz、Mg/In-Si co-doped等緩衝層技術以獲得高品
質的厚GaN on 6” Si,已做整體利佈局。
• 利用前述自有磊晶技術,結合特殊製程,開發 6” GaN/Si
LED發光效率 接近GaN/Sapp LED 。
• 利用nano rod+ NiOx製作E-mode GaN/Si HEMT,達崩
潰電壓 ~900V ; Vt ≧ 2 技術水準。
• 降低LED生產成本 : 若在成本低廉的6吋以上矽晶圓生成
氮化鎵,並採用與現代半導體生產線相容的製程,則晶
粒成本會比現有製程有效降低75% ,利於產業切入照明
等應用。
• 加速產業轉型 : 整合與鏈結國內光電與半導體廠的專長
與資源,切入GaN電子元件的高單價產品技術。
GaN epitaxy
on 6” Si substrate
GaN/Si HEMTs
GaN/Si LED
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
42
End
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Wafer size Epi-thickness BOW Carrier
density
Channel
mobility
Sheet
resistance
IMEC • 8-inch • Crack free < 50 μm
6-inch
272+-5 Ω/sq
AZZURRO • 6-inch > 6 μm 15 μm
DOWA • 6-inch
> 5 μm 7.4 μm 6x1012/cm2 1500 cm2/V-s 600 Ω/sq
NTT • 6-inch > 5 μm 34 μm ? 2180 cm2/V-s
440 Ω/sq
IEMN •4-inch 2x1013/cm2 1400 cm2/V-s 235 Ω/sq
ITRI • 6-inch > 4 μm ? 1.5x1013/cm2 1200 cm2/V-s 400 Ω/sq
Benchmark of power device of GaN on Si
Key issue : How to increase the GaN thickness on large scale Si substrate ?
=> stress engineering, then in-situ stress monitoring !
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Surfa
ce state
s
GaN HEMTs Advantages
44
“A 3–10-GHz GaN-Based Flip-Chip Integrated Broad-Band Power Amplifier,” IEEE Transactions on Microwave Theory
and Techniques,vol. 48, pp. 3573-2578, 2000.
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
0 1 2 3 4 5 6 7 8 9 100
20
40
60
80
100
120
140
160
180
200
Passivation:NiOx
Ni(50nm)/O2(5sccm)/non-RTP
Passivation:SiO2/SiNx
40%
Vg:1V
Lch
:2um
Lg-d
:20um
Ids (
mA
/mm
)
Vds(V)
0 500 1000 1500 2000 2500 3000
1E-9
1E-8
1E-7
1E-6
1E-5
1E-4
1E-3
0.01
0.1
1
Cu
rren
t (m
A)
Voltage(V)
2-20um-passivation SiO2/SiNx
2-30um-passivation SiO2/SiNx
2-20um-Passivation NiOx
2-30um-Passivation NiOx
NiOx as passivation具 depletion 效果(40%)與Leakage current 下降1E-4
NiOX G S
Substrate
u-GaN:1.5um
U-Al0.25GaN; 20nm u-GaN:1nm
D NiOX
•Mesa
•Ti(100nm)/Al(300nm)/RTP
•NiOx:Ni(50nm)/O2(5sccm)
Lift off-non RTP
NiOx Insulation layer of HEMTs
45
DOWA’s epi wafer
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
Epitaxial relationship of GaN(001) on Si(111)
46
工業技術研究院&機密資料 禁止複製、轉載、外流 │ ITRI & WALSIN CONFIDENTIAL DOCUMENT DO NOT COPY OR DISTRIBUTE
GaN/Si HEMTs Epi-structure Quality
47
U-Si
AlN (100nm)
GaN (1.5 µm)
AlGaN graded layer
with C-doped (2.5um)
Al0.25Ga0.75N (25 nm)