Etch process with pre-etch transient conditioning

摘要

A method for etching features with different aspect ratios in an etch layer is provided. A plurality of cycles is provided wherein each cycle comprises a pre-etch transient conditioning of the etch layer, which provides a transient condition of the etch layer, wherein the transient condition has a duration and etching the etch layer for a duration, wherein the duration of the etching with respect to the duration of the transient condition is controlled to control etch aspect ratio dependence.

主权项

1. A method for etching features with different aspect ratios in an etch layer, comprising:
a plurality of cycles, wherein each cycle comprises:
a pre-etch transient conditioning of the etch layer, which provides a transient condition of the etch layer, wherein the transient condition has a duration, wherein the pre-etch transient conditioning comprises
providing a pre-etch transient conditioning gas consisting essentially of He and O2; andforming the pre-etch transient conditioning gas into a plasma; andetching the etch layer for a duration, wherein the duration of the etching with respect to the duration of the transient condition is controlled to control etch aspect ratio dependence, wherein the etching follows the pre-etch transient conditioning, wherein the etching taking place within the duration of the transient condition provides a reverse aspect ratio dependent etch than etching past the duration of the transient condition.