Development on the Highly Precise Detection System for the Abnormal Discharge at the Plasma Etching Equipment

摘要

We've established a novel technology that can detect abnormal discharge of dry etching process. This technology consists of a system monitoring the signal of the plasma impedance as well as the reflection power at every 1msec. (a millisecond) and well-optimized diagnosis algorithm. Based on the algorithm, the system can detect the abnormal discharge even at unstable plasma ignition step and send alarm signal to the dry etcher for stopping the following wafer processing. The detection system based on this technology enables us to minimize the number of damaged wafers due to the abnormal discharging.