Patent ID: 9691625
Date: 2017-06-27
CPC Classifications: H01L

Claim:
1. A method for plasma etching of a target material in semiconductor 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) supplying a bi-modal process gas composition to a plasma generation region overlying the substrate; (c) for a first period of time, applying a first radiofrequency power to the bi-modal process gas composition within the plasma generation region to generate a plasma in exposure to the substrate, the plasma generated through application of the first radiofrequency power causing etching-dominant effects on the substrate; (d) for a second period of time, after completion of the first period of time, applying a second radiofrequency power to the bi-modal process gas composition within the plasma generation region to generate the plasma in exposure to the substrate, wherein the second radiofrequency power is applied instead of the first radiofrequency power, the plasma generated through application of the second radiofrequency power causing deposition-dominant effects on the substrate; 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.