IMPROVED DELINEATION PATTERN FOR EPITAXIAL DEPOSITIONS

摘要

An improved delineation pattern for epitaxial depositions is created by forming a mask (6) on a single-crystal silicon substrate (4) which leaves an area (10) of the substrate exposed, doping the area with a dopant to create a doped region (14) defined by a periphery, anisotropically, vertically etching the doped region to create a delineation pattern corresponding to the periphery, and then forming an epitaxial layer (39) over the delineation step (34) including a first step wall (36) generally perpendicular to the surface of the substrate and a second step wall (38) generally parallel to the surface of the substrate. The squared-off delineation step helps prevent wash-out of the delineation pattern as one or more epitaxial layers are deposited on the substrate.