Design and Numerical Simulation of Novel Reentrant Microwave Cavity

Abstract

Microwave plasma chemical vapor deposition (MPCVD) has gained considerable importance due to the capability of producing high quality diamond film, microwave cavity is one key factor for improving the techniques. Reentrant cavities with special structure were proposed, the effective chamber dimension can be changed. Ring shape quartz dielectric window was employed on the bottom side of the substrate holder and so fully shielded from the plasma, which make the cavity has excellent power handing capability. Distribution of electric fields in cavities were simulated. The modeling results show that, after optimization, electric field in chamber exhibits one maximum and homogeneous distribution on substrate, but very weak near the dielectric window, which meet the requirement for design. Proposed reentrant cavities have potential application in MPCVD diamond film with more microwave input power. This study will provide reference for further improvement of MPCVD techniques.