SEMICONDUCTOR DEVICES HAVING RECESSED STRUCTURES AND METHODS OF FORMING THE SAME

摘要

A method for forming a semiconductor device is provided. The method includes providing a substrate having a plurality of protrusions projecting from the substrate; forming a silicon layer over the substrate and each protrusion; performing an anisotropic etching to transfer the silicon layer into a silicon spacer positioned on a side wall of each protrusion; forming an oxide layer over the silicon spacer; and etching the substrate to form a recess on the substrate by using the oxide layer as a mask.