For a wide range of semiconductors (GaAs, GaP, InP, InSb, Cd_xHg_1-xTe, SiC), as well as contact structures based on them, that are of importance in engineering, the monograph gives, in a systematized and generalized form, the results of investigation of their properties modification under action of high-power microwave radiations and nanosecond laser pulses. The physical models for production, annihilation and annealing of point defects and impurity-defect complexes in irradiated materials are considered. An analysis is made of the features of radiation-stimulated mass transport, chemical reactions, formation of new phases in various contact structures, and they are related to the parameters of surface-barrier structures. Much space is given to the elastic stress relaxation due to microwave radiation, depending on the initial impurity-defect condition of materials, their surface morphology and irradiation mode. The authors substantially lean on their own experience in this area. They pay special attention to the use of microwave and laser processing of semiconductor materials for improvement of their structural perfection and development, on their basis, of ohmic and barrier contacts having improved parameters.
 The monograph is intended for researchers and specialists engaged in semiconductor electronics. It may be of use also to lecturers, post-graduates and undergraduates dealing with the above problems.