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.