A Frontal Attack on Limiting Defects in Nitrides: Theory and Computations
Abstract
Defects are limiting the performance of nitride semiconductor devices: they restrict doping levels, lead to device degradation, and interfere with achieving undoped or semi-insulating material. We have performed a comprehensive theoretical study aimed at facilitating the identification of defects and impurities, and at devising strategies for controlling their formation. Calculations were performed for isolated point defects, defect complexes, and impurities, in a bulk environment, as well as in the vicinity of extended defects and on the GaN surface. In addition to GaN, we performed calculations for InN and AlN, aimed at addressing InGaN and AlGaN alloys that are an essential constituent of device structures. Throughout, the computational results have been used for comparisons with and interpretations of experimental results. Significant results include the identification of a novel structure of Mg-H complexes; a critical assessment of the prospects of codoping; comprehensive results for diffusion of point defects and of hydrogen; a new model for the structure of screw dislocations; detailed values for the effects of impurities on the lattice parameters; the finding that hydrogen acts as a source of n-type conductivity in InN; and a comprehensive thermodynamic description of GaN surfaces in the presence of hydrogen.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 30, 2002
- Accession Number
- ADA405148
Entities
People
- Chris G. Van de Walle
- John E. Northrup
Organizations
- PARC