PULSED PLASMA SYSTEM WITH PULSED REACTION GAS REPLENISH FOR ETCHING SEMICONDUCTOR STRUCTURES

摘要

A pulsed plasma system with pulsed reaction gas replenish for etching semiconductor structures is described. In an embodiment, a portion of a sample is removed by applying a pulsed plasma etch process. The pulsed plasma etch process comprises a plurality of duty cycles, wherein each duty cycle represents the combination of an ON state and an OFF state of a plasma. The plasma is generated from a reaction gas, wherein the reaction gas is replenished during the OFF state of the plasma, but not during the ON state. In another embodiment, a first portion of a sample is removed by applying a continuous plasma etch process. The continuous plasma etch process is then terminated and a second portion of the sample is removed by applying a pulsed plasma etch process having pulsed reaction gas replenish.