Effects of high-temperature AIN buffer on the microstructure of AlGaN/GaN HEMTs

Date
2013
Advisor
Supervisor
Co-Advisor
Co-Supervisor
Instructor
Source Title
Semiconductors
Print ISSN
1063-7826
Electronic ISSN
Publisher
Pleiades Publishing
Volume
47
Issue
6
Pages
820 - 824
Language
English
Type
Article
Journal Title
Journal ISSN
Volume Title
Series
Abstract

Effects on AlGaN/GaN high-electron-mobility transistor structure of a high-temperature AlN buffer on sapphire substrate have been studied by high-resolution x-ray diffraction and atomic force microscopy techniques. The buffer improves the microstructural quality of GaN epilayer and reduces approximately one order of magnitude the edge-type threading dislocation density. As expected, the buffer also leads an atomically flat surface with a low root-mean-square of 0.25 nm and a step termination density in the range of 108 cm-2. Due to the high-temperature buffer layer, no change on the strain character of the GaN and AlGaN epitaxial layers has been observed. Both epilayers exhibit compressive strain in parallel to the growth direction and tensile strain in perpendicular to the growth direction. However, an high-temperature AlN buffer layer on sapphire substrate in the HEMT structure reduces the tensile stress in the AlGaN layer.

Course
Other identifiers
Book Title
Keywords
Citation
Published Version (Please cite this version)