IN SITU FORMED DRAIN AND SOURCE REGIONS INCLUDING A STRAIN INDUCING ALLOY AND A GRADED DOPANT PROFILE

摘要

The dopant profile of a transistor may be obtained on the basis of an in situ doped strain inducing semiconductor alloy wherein a graded dopant concentration may be established along the height direction. Consequently, the semiconductor alloy may be positioned in close proximity to the channel region, thereby enhancing the overall strain inducing efficiency, while not unduly compromising the finally obtained dopant profile. Furthermore, additional implant species may be incorporated prior to selectively growing the semiconductor alloy thereby avoiding implantation induced relaxation of the internal strain.