SiC半導体

Size: px

Start display at page:

Download "SiC半導体"

しおりこいまる
6 years ago
Views:

1 Silicon Carbide Semiconductor Hiroo Fuma, Toshio Murata, Atsushi Miura, Naohiro Sugiyama, Atsuto Okamoto, Toshihiko Tani, Hiroyuki Kano SiC SiC 1 1 4H-SiC E. P. D. ( Etch Pit Density ) cm 2 2 SiC ( 1500 ) CVD 3C-SiC Si(100) 4H 6H-SiCn cm 3 (3C) cm 3 (6H) p cm 3 (6H) SiC MOSFET 3C-SiC 400 6H-SiC Au/6H-SiC 1.3MV/cm ( Si 1000V 0.25MV/cm 5 )700V SiC8MV/cm Si This paper reports the results of the research on silicon carbide (SiC) semiconductor material. SiC is a promissing material for low leakage devices and a candidate for novel high power device development. The results obtained are summarized below. 1 One-inch-size 4H-SiC single crystals have been grown by a sublimation method. The etch pit density of the crystals is in the range of cm 2. 2 By using internally-built chemical vapor deposition apparatus, 3C-SiC, heteroepitaxial-growth on Si(100), 4H-SiC homoepitaxial-growth, and 6H-SiC homoepitaxial-growth have been achieved. 3 By using nitrogen-hot-ion-implantation process with substrate heating at 750, SiC MOSFETs have been fabricated. 6H-SiC MOSFETs have operated even at 500 and 3C-SiC MOSFETs have operated at Au/6H-SiC schottky diodes have been fabricated and a breakdown electric field of 1.3 MV/cm has been obtained, which is about five times stronger than 0.25 MV/cm in Si material for 1000 V breakdown design. The Au/6H-SiC shottky diode showed 700 V breakdown voltage. SiC-thermal-oxide exhibited a dielectric breakdown field of 8 MV/cm, which is as high as that of Si thermal oxide. CVD MOSFET

2 58 SiC LED Tairov Lely SiC LED 1 6H-SiC /2 SiC/Si 1994 SiC MOS Si >300V ( 1/10 1/100 ) SiC MOS 3C SiC/Si MOSFET 500 MOSFET SiC 1 4H-SiC SiC SiC Si SiC 2 Si 2 C {0001} φ10mm 1mm hr HF SiC (0001) Si (0001 ) C Si SiC SiC Experimental scheme for SiC bulk single crystal growth.

59 1 A EPMA SiC Si Si-SiC Si SiC-C Si Si 3mm 6hr 223022951torr 24hr φ10mmφ17mm 9mm φ17mm

4B {11 00} {112 0} Morphological and elemental analyses for an initial-stage (A in Fig.

3 59 1 A EPMA SiC Si Si-SiC Si SiC-C Si Si 3mm 6hr torr 24hr φ10mmφ17mm 9mm φ17mm φ25mm 1 SiC Si-C <0001> 3C 4H 6H 6H 4H 6H C 4H 4H µm SiC {0001} A {0001} c {11 00} Fig. 4B {11 00} {112 0} Morphological and elemental analyses for an initial-stage (A in Fig. 1) growth surface of SiC single crystal. A SiC ingot grown (for 24 hrs) on a φ 10mm Acheson seed crystal.

60 SiC Si 15 13 SiC Si 1 2 3 4 SiC SiC X Cross section of SiC crystal grown in the <0001 > direction.

4 60 SiC Si SiC Si SiC SiC X Cross section of SiC crystal grown in the <0001 > direction. Alkaline-etched cross section of SiC crystal grown in the <11 00> direction. SiC i ii iii SiC RIE Reactive Ion Etching SiC i X ii iii iv RHEED as grown SiC X RBS ESR KOH 0001 Si 3 c 4A c cm cm 2 c

5 61 SiC GDMS SIMS PL ESR 4H-SiC GDMS n-type SiC 6H 4H /cm 3 100cm 2 V s SiC SiC VPE CVD LPE MBE CVD pn CVD SiC CVD SiC Si SiC n SiC CVD 2 CVD Si SiH 4 C C 3 H 8 H 2 SiC n Ar 10 6 Torr SiC 1300 Si3C-SiC 6H-SiC Analytical results for impurities in SiC by ICP spectrometry (powder) and GDMS (grown crystal). Sample SiC source powder Grown crystal ( 4H ) Average diameter ( µm ) Impurity concentration (wt. ppm. ) Fe Al Ca Mg Ti V N* ) < * ) inert gas fusion method

6 62 4H-SiC 3C-SiC 6H-SiC ( 3C-SiC/Si ) 3C-SiC 6H-SiC 3C-SiC Si(100) 3C-SiC CVD Si 3C-SiC 3 Si(100) H HCl Si C 3 H 8 3C-SiC 1350 SiC SiH 4 3C-SiC Schematic figure of low pressure chemical vapor deposition system µm/h X 0 05' 3C-SiC n cm 3 500cm 2 /Vs 1Ωcm ( 6H-SiC ) 6H-SiC(0001) H-SiC 6H-SiC 6H-SiC 6H-SiC 6H-SiC RIE 0 2µm Wet O H-SiC H SiH 4 C 3 H 8 6H-SiC RIE RIE RIE RIE

63 0 5µm/h 6H-SiC 6H-SiC Au Au 10 14 10 15 cm 3 8µm 700V ( ) SiC n p n N P p B Ga Al n 3C 6H-SiC N 2 NH 3 2 3C-SiC 6H- SiCAuC-V N 2 NH 3 3C-SiC 10 17 10 20 cm 3 6H-SiC 10 17 10 19 cm 3 3C-SiC NH

1986 MOSFET SiCMOSFET Normarski microphotograph of the 6H-SiC epitaxial layer. In the photograph, left side area (α) is epitaxial layer without RIE treatment as the substrate preparation process.

7 63 0 5µm/h 6H-SiC 6H-SiC Au Au cm 3 8µm 700V ( ) SiC n p n N P p B Ga Al n 3C 6H-SiC N 2 NH 3 2 3C-SiC 6H- SiCAuC-V N 2 NH 3 3C-SiC cm 3 6H-SiC cm 3 3C-SiC NH cm Ωcm n p TEA 6H-SiC Al cm 3 p cm 3 TEA TMA Al SiC Al0 25eV Si IC MOSFET ( Metal-Oxide- Semiconductor Field-Effect-Transistor ) MOS Si Si SiO 2 SiC Si SiO 2 ) 1986 MOSFET SiCMOSFET Normarski microphotograph of the 6H-SiC epitaxial layer. In the photograph, left side area (α) is epitaxial layer without RIE treatment as the substrate preparation process. Rigth side area (β) is the epitaxial layer after RIE (0.2 µm) treatment. Carrier concentration of nitrogen doped layer in 3C, 6H-SiC as a function of the nitrogen/carbon ratio during CVD growth.

8 64 SiC MOSFET SiCSi C SiC RIE RIE RIE SiC Si CF 4 Si CF 4 (3 8Pa) RIE RIE SiC Si SiO 2 SiC Si Si MOS 1100 Wet O 2 3C-SiC F- N 8MV/cm Si MOSC-V 3C-SiC/Si MOS C-V 1 3C-SiC 3C- SiC/SiO 2 6H-SiC SiC Si n + Al n Ni 1000 pal MOSFET Poly-Si Poly-Si SiC 15nm 1300 SiC Poly-Si 750 N + 2 SiC SiC 2 140keV cm 2 80keV cm min Wet O 2 Al C-V characteristics of 3C-SiC MOS diode. Values for Theoretical Calculation ; Donor Concentration : cm 3 Relative Dielectric Constant of Oxide : 3.8 Intrinsic Carrier Concentration : 6.7 cm 3 Relative Dielectric Constant of SiC : 10

9 min MOSFET Si B p 3C-SiC 6H SiC (0001)Si µm Al p 6H-SiC cm 3 ) 3C-SiC MOSFET 400Id Vd 3C-SiC 1) p 0 7eVFig. 10 1) Id a [ (Vg Vt) Vd (1/2 + b) Vd 2 ] (1 a, b Vg Vt Vd 400 Id Vg 70cm 2 /Vs 6H-SiC 6H-SiC MOSFET Si 3C-SiC H-SiC MOSFET500 Au Si 3C-SiC SiC 6H-SiC 1 3MV/cm Si 1000V 0 25MV/cm 5 2 5MV/cm SiC MOSFET 8MV/cm Outline of SiC MOSFET fabrication process. I-V characteristics of 3C-SiC MOSFET. Solid line ; measured, dashedline ; calculated.

66 Si MOSFET 1 3MV/cm Si 5 MOSFET 500 IC JFET MOS 70cm 2 /Vs 1 Tairov, Y M and Tsvetkov, V F : J Cryst.

Silicon Carbide II, (1989), 178, Springer-Verlag 3 Bhatnagar, M, Alok, D and Baliga, B J, : Silicon Carbide and Relat. Mater., (1994), 73, IOP Publ.

Growth, (1993), 71 8 Kanaya, M Takahashi, J Fujiwara, Y and Moritani, A : Appl Phys Lett(1991), 56 9 Franck, F C : Acta Crystallogr, (1951), 497 10 Takahashi, J Kanaya, M and Fujiwara, Y : J Cryst.

10 66 Si MOSFET 1 3MV/cm Si 5 MOSFET 500 IC JFET MOS 70cm 2 /Vs 1 Tairov, Y M and Tsvetkov, V F : J Cryst. Growth, (1978), 209 2) Fuma, H Miura, A Tadano, H, Sugiyama, S and Takigawa M Amorphous and Cryst. Silicon Carbide II, (1989), 178, Springer-Verlag 3 Bhatnagar, M, Alok, D and Baliga, B J, : Silicon Carbide and Relat. Mater., (1994), 73, IOP Publ. Ltd 4 Drowart, J and Maria, G de : in Silicon Carbide-1958, Ed. by O Connor, J R and Smilten, J (1959), 16 5 SiC 3, (1994) 19 6 SiC 2, (1993), 28 7 Stein, R A and Lanig, P J Cryst. Growth, (1993), 71 8 Kanaya, M Takahashi, J Fujiwara, Y and Moritani, A : Appl Phys Lett(1991), 56 9 Franck, F C : Acta Crystallogr, (1951), Takahashi, J Kanaya, M and Fujiwara, Y : J Cryst. Growth, (1994), SiC2 (1993), Kikuchi, M Takahashi, Y Suga, T, Suzuki, S and Bando, Y : J Am Ceram Soc, Nakashima, S and Tahara, K : Phys Rev 1989, Nakata, T Koga, K Matsushita, Y Ueda, Y and Niina, T : Amorphous and Cryst. Slicon Carbide II, (1989, 26, Springer-Verlag 15 Biedermann, E : Solid State Commun., 1965, ) Nishino, S Suhara, H Ono, H and Matsunami, H : J Appl Phys (1987), ) Kuroda, N Shibahara, K Yoo, W Nishino, S and Matsunami, H : Ext Abstr 19th Conf Solid State Devices and Mater., Business Center for Academic Societies Japan, Tokyo, (1987), ) 6 SiC (1991), V-2 19) Shibahara, K Saito, T Nishino, S and Matsunami, H IEEE Electron Device Lett., EDL-7(1986), 692 Fuma, H., Miura, A Tadano, H Sugiyama, S and Takigawa, M : Ext. Abstr. of the 20th Conf. on Solid State Devices and Mater., (1988), 13 Fung, C D and Kopanski, J J : Appl. Phys Lett, (1984), 757 Fuma, H Kodama, M Tadano, H Sugiyama, S and Takigawa, M : Amorphous and Cryst. Silicon Carbide III (1992), 237, Springer-Verlag SDM ), 101 SiC 3 (1994), 15 Brown, D M Ghezzo, M Kretchmer, J Krishnemuthy, V, Michon, G and Gati, G 2nd Int. High Temp. Electron. Conf.,(1994), XI Tipton W Scozzie, C DeLancy, M and McGarrity, J : 2nd Int. High Temp. Electron. Conf., (1994), VIII-29 27) : SiC 3 (1994), SiC MRS 1963 SiC 1963 SiC

11 Materials Research Society, American Ceramics Society, Sigma Xi Ph. D ( ) SiC

untitled

untitled 213 74 AlGaN/GaN Influence of metal material on capacitance for Schottky-gated AlGaN/GaN 1, 2, 1, 2, 2, 2, 2, 2, 2, 2, 1, 1 1 AlGaN/GaN デバイス ① GaNの優れた物性値 ② AlGaN/GaN HEMT構造ワイドバンドギャップ半導体 (3.4eV) 絶縁破壊電界が大きい