Effect of Segmenting Powered Electrode on Plasma Uniformity in Large-Area Capacitively Coupled Plasma Discharge

Very high frequency RF sources for PECVD of silicon are attractive due to improved film quality and higher deposition rate. However, economic considerations are driving a rapid increase in substrate size to reduce production costs and increase process throughput. As a consequence, electromagnetic wave effects are becoming the dominant factor in determining processing uniformity in large-area plasma processing. We apply a self-consistent 3-D electromagnetic plasma model to investigate the effect of segmenting the powered electrode in eliminating the electromagnetic wave effects and improving plasma uniformity. Images of electron density and electric field distribution generated by an array of 3 × 3 segmented subelectrodes are presented.