C-doped GaN buffer layers with high breakdown voltages for high-power operation AlGaN/GaN HFETs on 4-in Si substrates by MOVPE

• Published in: Journal of crystal growth Vol. 298; pp. 831 - 834
• Main Authors: Kato, Sadahiro, Satoh, Yoshihiro, Sasaki, Hitoshi, Masayuki, Iwami, Yoshida, Seikoh
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 2007; Elsevier
• Subjects: A3. Metalorganic chemical vapor deposition; Applied sciences; B1. AlGaN; B1. GaN; B1. Nitride; B3. HFET; Cross-disciplinary physics: materials science; rheology; Electronics; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Other semiconductors; Physics; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Specific materials; Theory and models of film growth; Transistors; Vapor phase epitaxy; growth from vapor phase; B1. Nitride; 85.30.Tv; B1. GaN; B1. AlGaN; A3. Metalorganic chemical vapor deposition; 73.61.Ey; 81.15.Gh; 81.05.Ea; B3. HFET; Buffer layer; A3. Metalorganic chemical vapor deposition; Bl. AlGaN; Bl. GaN; Bl. Nitride; B3. HFET; Inorganic compounds; Gallium nitrides; Field effect transistors; 73.61.Ey; 81.05.Ea; 81.15.Gh; 85.30.Tv; VPE; Carbon additions; MOCVD; III-V compound; Surface states; Thin films; Nitrides; MOVPE method; Wafers; Aluminium nitrides; Growth mechanism; Drain current; Breakdown; Heterojunctions; Heterojunction field effect transistor; Heterostructures; III-V semiconductors
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2006.10.192

We investigated GaN buffer layers grown on Si substrates using a multi-wafer metalorganic vapor-phase epitaxy (MOVPE) system for 4-in five wafers (5×4″) growth in order to obtain field-effect transistors (FETs) with high breakdown voltages. It was confirmed that GaN films with smooth surfaces and without any cracks were obtained. To obtain high-resistive GaN buffer layers, C-doping was carried out by controlling the V/III ratio and the growth pressure. The breakdown voltage of the buffer layer was strongly correlated with the C concentration. As a result, the breakdown voltage was over 800 V when the C concentration was about 8E18 cm −3. We also fabricated a heterojunction FET (HFET) using an AlGaN/GaN heterostructure on a C-doped GaN buffer layer. The breakdown voltage of the FET in the off state was over 500 V and the maximum drain current of the FET was over 300 mA/mm. It was thus confirmed that an AlGaN/GaN HFET with a high-resistive buffer layer on a 4-in Si substrate could be obtained.