Electrical and Structural Properties of AlGaN/GaN Heterostructures Grown onto 8°-Off-Axis 4H-SiC Epilayers
In this work the electrical and structural properties of AlGaN/GaN heterostructures grown onto 8°-off-axis 4H-SiC epilayers were investigated. A morphological and structural analysis of the samples showed the presence of “V-shaped” near-surface defects in the AlGaN layer, with a preferential orientation along the miscut direction [11-20]. In the presence of these defects an anisotropy of the current-voltage characteristics of high electron mobility transistors (HEMTs), fabricated with two different orientations, was observed. The sheet carrier density ns and the channel mobility n were determined from the device characteristics. The results were discussed considering the possible implications for AlGaN/GaN HEMT technology.
Edouard V. Monakhov, Tamás Hornos and Bengt. G. Svensson
F. Roccaforte et al., "Electrical and Structural Properties of AlGaN/GaN Heterostructures Grown onto 8°-Off-Axis 4H-SiC Epilayers", Materials Science Forum, Vols. 679-680, pp. 808-811, 2011