Semiconductor device and methods of forming the same

Abstract

A method includes forming a stack of semiconductor layers over a substrate; etching the stack to form a first fin and a second fin, the first fin having a first width, the second fin having a second width, the second width being greater than the first width; etching a first recess in the first fin and a second recess in the second fin; performing a deposition process to grow a first epitaxial region in the first recess and a second epitaxial region in the second recess; wherein at a first point in the deposition process, a first raised height of the first epitaxial region is higher than a second raised height of the second epitaxial region; and wherein at a second point in the deposition process, a third raised height of the first epitaxial region is lower than a fourth raised height of the second epitaxial region.