2013 74 Tokyo Institute of Technology AlGaN/GaN C Annealing me Dependent Contact Resistance of C Electrodes on AlGaN/GaN, Tokyo Tech.FRC, Tokyo Tech. IGSSE, Toshiba, Y. Matsukawa, M. Okamoto, K. Kakushima, Y. Kataoka, A. Nishiyama, N. Sugii, H. Wakabayashi, K. Tsutsui, K. Natori, T. Hattori, H. Iwai, W.Saito 1
5% IT others 10% heat lighting 14% 2005 9996 kw hr ( ) motor 57% 5731 kwh GaN Si GaN [ev] 1.1 3.39 [MV/cm] 0.3 3.3 [cm 2 /V/s] 1350 900(HEMT:2000 [1 10 7 cm/s] 1 2.5 ) [W/cm/K] 1.5 2.1 2
GaN Metal Metal Metal Metal AlGaN GaN 2DEG Buffer Layer Si Substrate AlGaN/GaN HEMT, RonA (mωcm 2 ) 10 1 0.1 Si ρ c =10µΩcm 2 1µΩcm 2 0.1 µωcm 2 0.01 750V 60% GaN C g =35nF/cm 2 L ch =0.5µm V g -V th =5V 0.01 100 µωcm 2 1000 1000 100 GaN 1000 (V) 10000 W.Saito Solid-State Electronics 48(2004) AlGaN GaN 3
GaN φ Bn AlGaN Ef 850 /Al/Ni/Au (a) (b)haadf STEM GaN N GaN N N [1]L.Wang Apl 95 172107(2005) 4 [2]M.Hiroki IEICE Techical Report ED2008-11(2008)
N C 4.3eV, 3160 o C 3.9nm) C 5
C 298K Substance H 298 (kj/mol) Al 0.25 Ga 0.75 N 162.7 N 265.5 C 184.5 CN 435.1 B 2,C,Si 2 X(B,C,Si ) AlGaN C 2Al0.25 Ga 0.75N + C 1 = N + CN + Al + 2 3 2 Ga 190.7kJ/mol C CN 6
SPM,HF TEOS SiO 2 (100nm) BHF RIE(Cl 2 ) TEOS SiO 2 (100nm) BHF( ) C(20nm) N(50nm) RIE 20nm 500 o C~1100 o C (N 2 ) I V (TLM ) 7 SiO 2 (100nm) N C C AlGaN GaN distance AlGaN GaN Buffer layer Si sub 50nm N(50nm)/C(20nm) 18set 1set C/N C 0.45nm 0.85nm 7
C C(111) C(200) C(311) Log(counts) C(220) C(222) C C SiO 2 Si 18set 1set Annealing temperature:500 o C 30 50 70 90 θ 2θ(deg) K.Tuokedaerhan Apl 103 111908(2013) C( 500 o C C XRD 8
5.0 4.0 3.0 Current(mA) 2.0 1.0 0 1.0 2.0 3.0 4.0 1100 o C 1000 o C 950 o C 1050 o C 80 m 300 m 900 o C 800 o C 150 m 5.0 5.0 4.0 3.0 2.0 1.0 0 1.0 2.0 3.0 4.0 5.0 Voltage(V) I-V characteristic of C. C 1000~1050 9
Total resistance(ω) 1200 1000 800 600 400 200 0 Annealing temperature:1000 o C Annealing time:1min 293K 200K 56K 0 50 100 150 200 250 300 Contact distance(μm) Dependence of total resistance on distance 10
Contact specific resistivity(ωcm 2 ) 10 1 10 2 10 3 293K 56K 10 4 0 2 4 6 8 10 12 14 16 18 20 1000/Temperature(K) Dependence of contact specific resistivity on temperature 11
Contact specific resistivity(ωcm 2 ) 10 1 10 2 10 3 10 4 Annealing temperature:1000 o C 1 10 100 Annealing time(min) Annealing time dependent contact specific resistivity of C 12
500 o C 1000 o C 1min C/N 950 o C 50min C/N 1100 o C 1min C/N 1000 o C 1min C/N SEM) 950 o C O 2 O 13
C C 14
15
1, 2, 3, 4, C
1, N 50nm :C=1:1 20nm C C AlGaN GaN 18set 1set C 0.45nm 0.85nm 2, AlGaN SiO 2 SiO 2 (100nm) distance N(50nm)/C(20nm) AlGaN GaN Buffer layer Si sub
3, (/Al/Mo) C 4, C C [ cm] 80(Bulk),687(20nm, ) [g/cm 3 ] 4.92~4.938 [J/g] 0.7~0.9 CRC Materials Science and Engineering Handbook (2000)
Metal Metal Metal AlGaN GaN Buffer Layer Si Substrate Metal 2DEG, RonA (mωcm 2 ) 10 1 Si ρ c =10µΩcm 2 750V 60% GaN 0.1 1µΩcm 2 C g =35nF/cm 2 0.1 L ch =0.5µm µωcm 2 V g -V th =5V 0.01 0.01 µωcm 2 100 1000 10000 (V) GaN W.Saito Solid-State Electronics 48(2004) 750V 1000V V AlGaN/GaN c=10 6 cm 2 c=10 5 cm 2 19
GaN GaN [MV/cm] Si 10 [W/cm/K] (Si 1.5 ) [cm/s] (Si 2.5 ) Si SiC GaN [ev] 1.1 3.26 3.39 [MV/cm] 0.3 2 3.3 [cm 2 /V/s] 1350 650~720 900 [1 10 7 cm/s] 1 2 2.5 [W/cm/K] 1.5 4.5 2.1 20 20
Au Ni//Pt/Mo Al Au Ni Al Al Fig1. The /Al specific resistivity on n GaN vs annealing time at 900 o C M.E.Lin Appl. Phys. Lett. 64(8) (1994) Fig2. Al//Al/Ni/Au /Al/Ni/Au M.Hiroki IEICE Techical Report ED2008-11(2008) 10 6 < c cm 2 <10 5 21 21
GaN L.Wang Apl 95 172107(2005) L.Wang Apl 95 172107(2005) N N GaN GaN GaN GaN 22
C AlGaN V φ Bn AlGaN Ef C AlGaN Si( 117.6 10-12 m) (C: 70 10-12 m) 23
24,Al,AlN AlGaN Metal W Semiconductor Schottky 24 Si 2 AlGaN GaN Si 2 AlGaN GaN GaN N N GaN N N N
/cm 2 /cm 2 (2012) 25
rs rf rfs θ (2012) rf: ( /m 2 rs: /m 2 rfs: /m 2 Frank van der Merwe(FM) s fs / f 1 =0 26
θs Air or overlayer γ s γ s γb (a) X: θi Substrate γ b γ i γ i : : (b) (c) (d) Lc: T.P.Nolan and R.Sinclair J.Appl.Phys.71(2)(1991) 27
A, B, C, D, (2012) 28
:C(0.0075nm/sec) (0.013nm/sec) C(60sec) (65sec)/(39sec) C 18set C AlGaN GaN 1set C C 0.45nm 0.85nm 29
( ) Current ma) 8 6 4 2 0-2 -4-6 -8 80 m -5.0-4.0-3.0-2.0-1.0 0 1.0 2.0 3.0 4.0 5.0 Voltage V) 1050 o C 300 m 800 o C 900 o C 150 m Fig. 5 I-V characteristic of C. 1000 o C 1100 o C 1050 o C 1050 o C Total Resistance(Ω 1V 1.0 10 8 1.0 10 7 1.0 10 6 1.0 10 5 1.0 10 4 1.0 10 3 1.0 10 2 1.0 10 1 1.0 10 0 SiO2 N(50nm)/C (17.68nm) distance AlGaN(26nm) GaN(1.3µm) Ohmic 300 400 500 600 700 800 900 1000 1100 Annealing Temperature( o C) Fig. 6 Total resistance on annealing temperature. 1050 o C 1.64 10 3 Ω 5C8 1050 30