Effect of Plasma Parameter Control on the Growth of Zincblende Type GaN Films by ECR Plasma Enhanced Metalorganic Chemical Vapor Deposition

Abstract

Zincblende type GaN films were grown at low temperatures by mesh-bias-controlled electron-cyclotron-resonance metalorganic chemical vapor deposition (ECRMOCVD) using ammonia and trimethylgallium as source gases. Dependence of plasma parameters such as electron temperature, electron density and plasma space potential in a discharge chamber and a growth chamber, on the mesh bias was investigated using a Langmuir probe and a Faraday cup. Dependence of the properties of GaN films, such as crystal structure, crystal orientation and residual stress, on the mesh bias applied during nitridation and growth was also investigated. The growth of zincblende GaN films was enhanced under conditions of a negative mesh bias at which the space potential was lowest and the impingement of ions was suppressed. The crystallinity of GaN films and their crystal orientation were best under the same bias conditions.