Growth of (In, Al)GaN Alloys by RF-plasma Assisted Molecular Beam Epitaxy for Application in High Electron Mobility Transistor Structures
Author | : Christiane Poblenz |
Publisher | : |
Total Pages | : 342 |
Release | : 2005 |
ISBN-10 | : OCLC:61281524 |
ISBN-13 | : |
Rating | : 4/5 (24 Downloads) |
Book excerpt: An all-MBE growth process for AlGaN/GaN HEMTs on SiC was also developed utilizing an AlN nucleation layer and a two-step growth process for the GaN to reduce and control threading dislocation density. The GaN growth process was structurally and electrically optimized to achieve semi-insulating HEMT buffers. Two methods were developed to reduce buffer leakage. The first was through implementation of carbon doping via CBr4, and the second was by optimization of the AlN nucleation layer growth conditions in unintentionally doped (carbon-free) structures. Optimization of the direct-growth process and elimination of buffer leakage led to record output power densities in MBE-grown AlGaN/GaN HEMTs and device performance which is on par with state-of-the art HEMTs grown by metalorganic chemical vapor deposition (MOCVD).