Cyclic etch process to remove dummy gate oxide layer for fin field effect transistor fabrication

Abstract

Methods are provided to implement a cyclic etch process to remove oxide layers for semiconductor device fabrication. For example, a method comprises performing a cyclic etch process to incrementally etch an oxide layer, wherein the cyclic etch process comprises sequentially performing at least two instances of an etch cycle. The etch cycle comprises performing an etch process to partially etch a portion of the oxide layer using an etch chemistry and environment which is configured to etch down the oxide layer at an etch rate of about 25 angstroms/minute or less, and performing a thermal treatment to remove by-products of the etch process. The cyclic etch process can be implemented as part of a replacement metal gate process to remove a dummy gate oxide layer of a dummy gate structure as part of, e.g., a FinFET semiconductor fabrication process flow.