Design and Implementation of Remote Plasma Sources for Semiconductor Chamber Cleaning

This paper presents design and implementation of remote-plasma-source (RPS) generator for semiconductor manufacturing chamber cleaning. The generator consists of a full-bridge resonant inverter, an inductive coupling transformer, and a chamber with low pressure gases. To design the power converter for generating plasma sources, the equivalent load of a plasma chamber is required. A traditional approach to acquire equivalent plasma load is measuring plasma density through Langmuir probe. But the intrusive characteristic and power stress limitation make Langmuir probe not a convenient method to be applied in some plasma source design. This study proposes an engineering approach to deriving equivalent plasma load which takes switching frequency and gas flow rate into account without special devices needed. The transformer and the chamber are modeled with an RLC load which is used for designing the resonant tanks of the inverter and the igniter. The system configuration and modeling processes are presented in detail, from which the inverter and igniter designs are presented correspondingly. Simulated and experimental results have verified the analyses, design approaches and discussions of the RPS generator.