Fabrication and Characterization of GaN HEMTs with short gate length

• Project/Area Number: 13450141
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 電子デバイス・機器工学
• Research Institution: Nagoya University
• Principal Investigator: MIZUTANI Takashi Nagoya University, Graduate School of Engineering, Professor, 工学研究科, 教授 (70273290)
• Co-Investigator(Kenkyū-buntansha): OHNO Yutaka Nagoya University, Graduate School of Engineering, Research Associate, 工学研究科, 助手 (10324451) ; KISHIMOTO Shigeru Nagoya University, Graduate School of Engineering, Research Associate, 工学研究科, 助手 (10186215) ; MAEZAWA Koichi Nagoya University, Graduate School of Engineering, Associate Professor, 工学研究科, 助教授 (90301217)
• Project Period (FY): 2001 – 2002
• Project Status: Completed (Fiscal Year 2002)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,900,000); Fiscal Year 2002: ¥3,900,000 (Direct Cost: ¥3,900,000)
• Keywords: GaN HEMT / Si_3N_4 / current collapse / temperature distribution / miro-Raman / gate leakage current / GaN MISHEMT / T-shaped gate / 電流しゃ断周波数 / 実効電子速度 / 低周波雑音 / EL発光 / 電界集中 / 高温動作

Research Abstract

Fabrication process of GaN HEMTs was studied to improve the device performance, and the fabricated device was characterized in detail. The main results are as follows. (i) Surfacepassivation of GaN HEMTs with Si_3N_4 film was effective in suppressing the current collapse that limit the output power. (ii) Temperature distribution in GaN HEMTs on a sapphire substrate was successfully measured by micro-Raman scattering spectroscopy. Temperature resolution better than 10K was obtained. The highest temperature was obtained at the edge on the drain side where high-field region was formed. (iii) A large gate leakage current was observed in the GaN HEMTs, which was suppressed by employing MISHEMT structure, where Si_3N_4 was used as a gate insulator. (iv) Measurement of I-V characteristics of micro-Schottky contacts revealed that the threading dislocation did not affect the gate leakage current. (v) Current gain cutoff frequency of 54GHz was obtained in the GaN HEMT with 0.2-μm-long T-shaped gate.

Research Products

• [Publications] T.Nakano, T.Mizutani, et al.: "Electroluminescence in Al GaN/GaN High Electron Mobility Transistros"Jpn.J.Appl.Phys.. 41. 1990-1991 (2002)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Y.Ohno, T.Mizutani, et al.: "Temperature Distribution Measurement in Al GaN/GaN High Electron Mobility Transistors by Micro-Raman Scattering spectroscopy"Jpn.J.Appl.Phys.. 41. L452-L454 (2002)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] S.Mizuno, T.Mizutani, et al.: "Large Gate Leakage Current in Al GaN/GaN High Electron Mobility Transistors"Jpn.J.Appl.Phys.. 41. 5125-5126 (2002)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] T.Mizutani, H.Makihara et al.: "Measurement of Frequency Dispersion of Al GaN/GaN High Electron Mobility Transistors"Jpn.J.Appl.Phys.. 42. 424-425 (2003)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] T.Mizutani, Y.Ohno et al.: "Current Collapse in Al GaN/GaN HEMTS Investigated by Electrical and Optical Characterizations"Phys.Stat.Sol. (a). 194・2. 447-451 (2002)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Y.Ohno, T.Mizutani et al.: "Temperature Distributions in Al GaN/GaN HEMTS Measured by Micro-Raman Scattering Spectroscopy"Phys.Stat.Sol. (c). 0・1. 57-60 (2002)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] T.Nakano, et al.: "Elecroluminescence in AlGaN/GaN High electron Mobility Transisters"Jpn.J.Appl.Phys.. 41. 1990-1991 (2002)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Y.Ohno, et al.: "Temperature Distribution Measurement in AlGaN/GaN High-Electron-Mobility Transistors by Micro-Raman Scattering Spectroscopy"Jpn.J.Appl.Phys.. 41. L452-L454 (2002)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] S.Mizuno, et al.: "Large Gate Leakage Current in AlGaN/GaN High Electron Mobility Transistors"Jpn.J.Appl.Phys.. 41. 5125-5126 (2002)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] T.Mizutani, et al.: "Measurement of Frequency Dispersion of AlGaN/GaN High Electron Mobility Transistors"Jpn.J.Appl.Phys.. 42. 424-425 (2003)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] T.Mizutani, et al.: "Current Collapse in AlGaN/GaN HEMTs Investigated by Electrical and Optical Characterizations"phys.stat.sol.(a). 194 No.2. 447-451 (2002)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Y.Ohno, et al.: "Temperature distributions in AlGaN/GaN HEMTs measured by micro-Raman scattering spectroscopy"phys.stat.sol.(a). 194 No.1. 57-60 (2002)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] T.Nakano, T.Mizutani et al.: "Electroluminescence in Al GaN/GaN High Electron Mobility Transistors"Jpn. J. Appl. Phys.. 41. 1990-1991 (2002)
• [Publications] Y.Ohno, T.Mizutani et al.: "Temperature Distribution Measurement in Al GaN/GaN High Electron Mobility Transistors by Micro-Raman Scattering Spectroscopy"Jan. J. Appl. Phys.. 41. L452-L454 (2002)
• [Publications] S.Mizuno, T.Mizutani et al.: "Large gate Leakage current in al GaN/GaN High Electron Mobility Transistors"Jpn. J. Appl. Phys.. 41. 5125-5126 (2002)
• [Publications] T.Mizutani, H.Makihara et al.: "Measurement of Frequency Dispersion of Al GaN/GaN High Electron Mobility Transistors"Jpn. J. Appl. Phys.. 42. 424-425 (2003)
• [Publications] T.Mizutani, Y.Ohno et al.: "Current Collapse in Al GaN/GaN HEMTS Investigated by Electrical and Optical Characterizations"Phys. stat. sol. (a). 194・2. 447-451 (2002)
• [Publications] Y.Ohno, T.Mizutani et al.: "Temperature Distributions in Al GaN/GaN HEMTS Measured by Micro-Raman Scattering Spectroscopy"Phys. stat. sol. (c). 0・1. 57-60 (2002)
• [Publications] M.Akita, T.Mizutani et al.: "High-Frequency Measurements of AlGaN/GaN HEMTs at High-Temperatures"IEEE Electron Device Lett.. 22. 376-377 (2001)
• [Publications] M.Aki, T.Mizutani et al.: "Temperature Dependence of AlGaN/GaN HEMTs Performances"Phys. Stat. Sol(a). 188. 207-211 (2001)
• [Publications] H.Makihara, T.Mizutani et al.: "The Low-Frequency Noise Characteristics of AlGaN/GaN HEMTs"Int. Phys. Conf. Series. (2002)
• [Publications] Y.Ohno, T.Mizutani et al.: "Electroluminescence in AlGaN/GaN HEMTs"Int. Phys. Conf. Series. (2002)