Mechanism and Effect of 4-Level RF Pulsing on Etching Process in Advanced Node

Dry etching is a science and technology about plasma behavior controlling and it directly affects the performance of IC device, especially in advanced node. However, current method of plasma precise controlling is still lacking. Here, it reports a novel 4-level RF pulsing function. Through multiple combinations of source power and bias power within each pulse, it can independently control radical density, ion bombardment and power off pump out degree. It is helpful to gain higher selectivity and sidewall protection in high-aspect-ratio (HAR).This new advanced RF feature in ICP provide a better process tuning solution for some key applications.