Laboratoire EPCM, Service A62, Faculté des Sciences de Saint Jérôme, Université d'Aix-Marseille III, 13397 Marseille cedex 20, France
Abstract:
This work concerns investigations on electrical properties of amorphous GaAs1−xNx thin films grown on GaAs substrates. Film deposition was carried out by RF sputtering of a GaAs target by adding a nitrogen carrier gas (NH3) to an Ar plasma. Chemical etching of substrates followed by different plasma treatments (like reverse bias and/or NH3 glow discharge) prior to film deposition have been studied. The effects of substrate and growth temperature and of total pressure in the reactor have been analysed. Electrical characteristics (C–V and C–V(T)) have enabled us to put in evidence the evolution of interface states of the a-GaAs1−xNx/c-GaAs junctions. The amorphous GaAs1−xNx thin films are potentially interesting to be considered for GaAs-based MIS structures, due to their relatively high resistivity values, or as passivating layers on GaAs devices.