Methods and Systems for Advanced Ion Control for Etching Processes

摘要

A substrate is disposed on a substrate holder within a process module. The substrate includes a mask material overlying a target material with at least one portion of the target material exposed through an opening in the mask material. A plasma is generated in exposure to the substrate. For a first duration, a bias voltage is applied at the substrate holder at a first bias voltage setting corresponding to a high bias voltage level. For a second duration, after completion of the first duration, a bias voltage is applied at the substrate holder at a second bias voltage setting corresponding to a low bias voltage level. The second bias voltage setting is greater than 0 V. The first and second durations are repeated in an alternating and successive manner for an overall period of time necessary to remove a required amount of the target material exposed on the substrate.

主权项

1. A method for plasma etching of a target material in semiconductor device fabrication, comprising:
(a) disposing a substrate on a substrate holder within a process module, wherein the substrate includes a mask material overlying a target material with at least one portion of the target material exposed through an opening in the mask material; (b) generating a plasma in exposure to the substrate; (c) for a first duration, applying a bias voltage at the substrate holder at a first bias voltage setting corresponding to a high bias voltage level and supplying a lower primary coil power to generate the plasma in exposure to the substrate; (d) for a second duration, after completion of the first duration, applying a bias voltage at the substrate holder at a second bias voltage setting corresponding to a low bias voltage level and supplying a higher primary coil power to generate the plasma in exposure to the substrate, wherein the second bias voltage setting is greater than 0 V, and wherein the second bias voltage setting is sufficiently low to avoid ion-induced removal of the mask material; and (e) repeating operations (c) and (d) in an alternating and successive manner for an overall period of time necessary to remove a required amount of the target material exposed on the substrate.