Stovpovyi M. Development and investigation of heat-resistant barrier and ohmic contacts for microwave devices on the basis of GaAs.

The thesis deals with development and research of heat-resistant barrier and ohmic contacts for microwave devices. It was shown that widely used metallisation systems Au-AuGe and Au-Ti (for ohmic and barrier contacts accordingly) are heat-resistant only to temperatures about 350 ? C due to diffusion and new phases creation processes. Proposed and studied in this work systems Au-TaNx(TiBx), Au-TiNx(TiBx) for ohmic and barrier contacts accordingly can stably work at temperatures up to 550 °С without change of electrophysical parameters. Use of such contacts allows creation of GaAs microwave devices of increased reliability. Researches of ohmic contacts for heterostructure (GaAs-AlGaAs) field-effect transistors were carried out. The criterion of technology optimality was experimentally determined and radiating stability of such contacts was investigated. The technique of the technology control is offered. It was shown, that influence of ? - radiation Co60 in a range of dozes (2-3)·107 Р improves parameters of ohmic contact.