Patent ID: 6656815
Filing Date: 2003-12-02
Classification: G03F,H01L

Abstract:
A method of forming a deep subsollector region with self-aligned alignment marks comprising the steps of:(a) lithographically forming a first patterned layer comprising a thick dielectric material on a surface of a material stack formed on a semiconductor substrate, said first patterned layer including at least one opening therein and said semiconductor substrate having at least an alignment area; (b) performing a high-energy/high-dose implant through said at least one opening and said material stack so as to form at least one deep subcollector region in said semiconductor substrate; (c) lithographically forming a second patterned layer predominately outside the first patterned layer in said alignment area; and (d) etching through said material stack in said alignment area to form alignment marks in the underlying semiconductor substrate using said first patterned layer as an alignment mark mask, said alignment marks are self-aligned to edges of said at least one deep subcollector region.