Patent ID: 7285480

Claim:
A method of forming Integrated Circuit (IC) chips, said method comprising the steps of: a) defining areas of a first transistor type in a surface of a semiconductor wafer, defining first transistor type areas comprising the steps of: i) forming a hard pattern on said semiconductor wafer surface, first transistor type areas being exposed by said hard pattern, and ii) etching exposed said first transistor type areas of said wafer surface to a first depth; b) defining areas of a second transistor type in said surface, remaining areas of said semiconductor wafer being of a third transistor type, defining second transistor type areas comprising the steps of: i) removing selected portions of said hard pattern, second transistor type areas being exposed by removal of said selected portions, and ii) etching exposed said second transistor type areas of said wafer surface to a second depth, said exposed first transistor type areas being further etched by said second depth; c) forming insulating material strata at said first transistor type and said second transistor type areas; and d) selectively forming device gates, ones of said device gates being located above said insulating material strata.