Method for forming finfet and gate-all-around fet with selective high-k oxide deposition

Abstract

A method of forming a semiconductor device structure is provided. The method includes forming an isolation feature over a semiconductor substrate. The semiconductor substrate includes a fin structure over the isolation feature. Two opposing spacer elements are formed over the isolation feature and across the fin structure so as to define a gate opening. The gate opening exposes the fin structure and the isolation feature and inner sidewalls of the gate opening have carbon-containing hydrophobic surfaces. A gate structure is formed in the gate opening with the carbon-containing hydrophobic surfaces.