Buffer breakdown voltage of AlGaN/GaN HFET on a 4 inch Si(111) substrate grown by MOCVD

• Published in: Physica status solidi. C Vol. 4; no. 7; pp. 2658 - 2661
• Main Authors: Iwami, Masayuki, Kato, Sadahiro, Satoh, Yoshihiro, Sasaki, Hitoshi, Yoshida, Seikoh
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.06.2007; WILEY‐VCH Verlag
• Subjects: 61.10.Nz; 61.72.Lk; 73.40.Kp; 73.61.Ey; 81.15.Gh; 85.30.Tv
• ISSN: 1862-6351; 1610-1634; 1610-1642
• DOI: 10.1002/pssc.200674712

The buffer breakdown voltage and the electron mobility in a two dimensional gas (2DEG) of AlGaN/GaN HFETs on 4 inch Si(111) substrates grown by metalorganic chemical vapor deposition was investigated. The relationship between the electrical properties of HFETs and the crystalline quality of the GaN layer are studied by X‐ray diffraction and photoluminescence measurements. The buffer breakdown voltage decreases with an increase in the FWHM of the X‐ray (0002) diffraction peak. The electron mobility in a 2DEG decreases with an increase in FWHM of the X‐ray (10$ \bar 1 $2) diffraction peak. These results indicate that a screw component of the threading dislocations in the GaN layer is a primary source for buffer leakage, and that edge dislocations in the GaN layer have a scattering effect on the 2DEG transport. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)