Doped Core Trigate FET Structure and Method

摘要

Techniques for fabricating a field effect transistor (FET) device having a doped core and an undoped or counter-doped epitaxial shell are provided. In one aspect, a method of fabricating a FET device is provided. The method includes the following steps. A wafer is provided having a semiconductor material selected from the group consisting of silicon, silicon germanium and silicon carbon. At least one fin core is formed in the wafer. Ion implantation is used to dope the fin core. Corners of the fin core are reshaped to make the corners rounded or faceted. An epitaxial shell is grown surrounding the fin core, wherein the epitaxial shell includes a semiconductor material selected from the group consisting of silicon, silicon germanium and silicon carbon.