METHOD OF ETCHING A LAYER USING SACRIFICIAL ELEMENTS

摘要

One embodiment of the invention is a method for forming a raised structure on a semiconductor wafer. In the method, a patterned masking layer is formed over a wafer layer. The patterned masking layer typically includes a first mask and at least one side mask adjacent to the first mask. After forming the patterned masking layer, exposed portions of the wafer layer adjacent to the masks are removed using the patterned masking layer. This leaves a first raised structure (relative to an adjacent removed area) and a sacrificial raised structure adjacent to the first raised structure. After removing the exposed portions of the wafer layer, the sacrificial raised structure is selectively removed while leaving the first raised structure intact. The sacrificial raised structure und overlying side mask facilitate the formation of the vertical sidewall on the raised structure.