Characteristics of a mesh-bias-controlled electron cyclotron resonance plasma for the growth of gallium nitride epitaxial films

Abstract

Characteristics of mesh-bias-controlled electron cyclotron resonance (ECR) plasma for the growth of gallium nitride (GaN) were investigated. Dependence on the mesh electrode bias of the plasma parameters such as electron temperature, electron density, and plasma space potential in the ECR plasma chamber and in the growth chamber was investigated using a Langmuir probe. The ion energy distribution function incident on the substrate surface was also investigated using a Faraday cup. Variation in the plasma parameters as a function of the position in the growth chamber was investigated. From the probe characteristics, the deactivation process of electrons in the growth chamber was clearly observed. From the crystal growth with the mesh electrode bias and substrate bias, it also became clear that the growth of zinc-blende GaN films was enhanced at the bias condition at which the number of electrons to the substrate surface was increased and the impinging ions were suppressed.