Revenko A. Properties of GaN-films, obtained by nitridation of porous GaAs

The thesis is devoted to the investigation of optical , crystal and morphological properties of GaN thin films, obtained by nitridation of porous GaAs. Mathematic model on convertation process GaAs in GaN during nitridation in nitrogen plasma was developed and presented in the work. Analysis of pre-sented model revealed optimized parameters of nitridation, in particularly, time and temperature. It was determined, that at temperature under 800 K intensity of convertation process is insufficient for obtaining GaN films, instead GaAsN compound are formed. At temperature above 1000 K the roughness of films significantly increases, and consequently, surface morphology of GaN films becomes poor quality - all this facts relates to intensive decomposition of GaAs substrate at that temperature. Porous sample of GaAs n- and p-type was obtained, their morphological and optical properties was investigated. The influence of low-dimensional effects of porous structures on photoluminescence is analyzed. The high efficiency of combining of application of porous GaAs substrate and nitridation for ob-taining semiconductors heterostructure GaN/por-GaAs/GaAs thin films are presented. Obtained by this way GaN/por-GaAs structures is a promising material for homoepitaxy of high quality , strain-free GaN thick films.