US Patent 11688625 Method for manufacturing semiconductor device

A method for manufacturing a semiconductor device is provided. The method includes forming at least one epitaxial layer over a substrate; forming a mask over the epitaxial layer; patterning the epitaxial layer into a semiconductor fin; depositing a semiconductor capping layer over the semiconductor fin and the mask, wherein the semiconductor capping layer has a first portion that is amorphous on a sidewall of the mask; performing a thermal treatment such that the first portion of the semiconductor capping layer is converted from amorphous into crystalline; forming an isolation structure around the semiconductor fin; and forming a gate structure over the semiconductor fin.