Remote Plasma Source Chamber Modeling and Generator Design

Abstract

This paper presents modeling of the plasma load in vacuum chamber of a remote plasma source (RPS) and its generator is designed and implemented correspondingly. Traditionally, equivalent plasma load modeling usually acquired parameters measured by Langmuir probe which is hard to conduct and is basically intrusive. A simple method to model the plasma load into frequency and flow rate related equivalent RLC load without special device is proposed in this study. And two different resonant inverters which are operated around 400 kHz as an igniter and a sustainer of the plasma source generator are designed based on the equivalent load. The igniter generates high voltage 5 kV with argon gas as a trigger to start the plasma progress and the sustainer provides a maximum power of 2.5 kVA to keep plasma generating with nitrogen gas. To avoid interruption of plasma generation under gas flow rate varying from 100 to 600 sccm, a simple PI control with frequency modulation on the sustainer to regulate its output current is adopted. Both system design and equivalent load modeling are verified with simulated and experimental results in the paper.