| 학회 |
한국재료학회 |
| 학술대회 |
2013년 가을 (11/06 ~ 11/08, 제주롯데호텔) |
| 권호 |
19권 2호 |
| 발표분야 |
A. 전자/반도체 재료(Electronic and Semiconductor Materials) |
| 제목 |
Effect of HT-AlN buffer thickness on the growth of modulation-doped AlGaN/GaN Heterostructure on SiC substrate |
| 초록 |
AlGaN/GaN heterojuction field-effect transistor (HFET) is excellent candidate for high power, high frequency, and high temperature device applications. However, there is an issue related to the substrate for growing high quality GaN layer, because the appropriate GaN substrate for the real device application is still not available so far. SiC substrate is preferred in growing the AlGaN/GaN HFET structure for RF/power applications because it has smaller lattice mismatch to GaN (3.49%) and higher thermal conductivity than other substrates such as sapphire and silicon. In this study, Modulation-doped AlGaN/GaN heterostructure was grown on semi-insulating 6H-SiC substrate using initial HT-AlN buffer layer and semi-insulating undoped GaN layer. We found that the GaN layer grown on 60 nm-thick HT-AlN buffer has the lowest threading dislocations (TDs) (screw TDs:9.06×107 cm-2, edge TDs : 1.41×108 cm-2) and the lowest tensile stress which indicates that 60nm thick HT-AlN buffer can minimize the lattice mismatch between GaN and SiC. In addition, the gallium vacancy in the grown GaN layer acts as deep acceptor that compensates the shallow residual donors resulting in semi-insulating nature. The 2DEG of grown AlGaN/GaN heterostructure showed excellent electrical properties such as electron mobility of 2220 cm2•V-1•s-1 and 2DEG concentration of 8.6×1012 cm-2. The fabricated AlGaN/GaN HFET with a gate length of 0.2 μm and a SiO2 passiviation layer exhibited good small-signal characteristics such as current gain cut-off frequency ( ƒT ) of 47 GHz and maximum oscillation frequency (ƒmax ) of 121 GHz. |
| 저자 |
You-mi Kwon1, Dong-Seok Kim2, Hee-Sung Kang1, Chul-Ho Won2, Ryun-Hwi Kim1, Sang-min Jeon2, Jung-Hee Lee1
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| 소속 |
1School of Electronics Engineering, 2Kyungpook National Univ. |
| 키워드 |
HT-AlN; AlGaN/GaN hetetojuction; HFET; 6H-SiC
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| E-Mail |
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