Method for selectively forming strain in a transistor by a stress memorization technique without adding additional lithography steps

Abstract

A selective stress memorization technique is disclosed in which the creation of tensile strain may be accomplished without additional photolithography steps by using an implantation mask or any other mask required during a standard manufacturing flow, or by providing a patterned cap layer for a strained re-crystallization of respective drain and source areas. In still other aspects, additional anneal steps may be used for selectively creating a crystalline state and a non-crystalline state prior to the re-crystallization on the basis of a cap layer. Thus, enhanced strain may be obtained in one type of transistor while not substantially negatively affecting the other type of transistor without requiring additional photolithography steps.