Method for forming hardmask formation by hybrid materials in semiconductor device

Abstract

A semiconductor device includes a substrate, first and second semiconductor strips, a dummy fin structure, first and second channel layers, a gate structure, and crystalline and amorphous hard mask layers. The first and second semiconductor strips extend upwardly from the substrate and each has a length extending along a first direction. The dummy fin structure is laterally between the first and second semiconductor strips. The first and second channel layers extend in the first direction above the first and second semiconductor strips and are arranged in a second direction substantially perpendicular to the substrate. The crystalline hard mask layer extends upwardly from the dummy fin structure and has an U-shaped cross section. The amorphous hard mask layer is in the crystalline hard mask layer. The amorphous hard mask layer has an U-shaped cross section conformal to the U-shaped cross section of the crystalline hard mask layer.