Doped core trigate FET structure and method

A method of fabricating a FET device, the method comprising the steps of:

• providing a wafer comprising a semiconductor material selected from the group consisting of silicon, silicon germanium and silicon carbon;
• forming at least one fin core in the wafer;
• using ion implantation to dope the fin core;
• growing an epitaxial shell surrounding the fin core, wherein the epitaxial shell comprises a semiconductor material selected from the group consisting of silicon, silicon germanium and silicon carbon;
• depositing a shallow trench isolation (STI) oxide onto the epitaxial shell;
• polishing the STI oxide and the epitaxial shell down to a top surface of the fin core and thereby exposing the fin core;
• recessing the epitaxial shell and the fin core in the STI oxide forming a recessed region;
• and
• growing an epitaxial layer on the epitaxial shell and the fin core in the recessed region, wherein the epitaxial layer comprises a semiconductor material selected from the group consisting of silicon, silicon germanium and silicon carbon.

A method of fabricating a FET device, the method comprising the steps of:

• providing a wafer comprising a semiconductor material selected from the group consisting of silicon, silicon germanium and silicon carbon;
• forming at least one fin core in the wafer;
• using ion implantation to dope the fin core;
• growing an epitaxial shell surrounding the fin core, wherein the epitaxial shell comprises a semiconductor material selected from the group consisting of silicon, silicon germanium and silicon carbon;
• depositing a nitride material onto the epitaxial shell;
• polishing the nitride material and the epitaxial shell down to a top surface of the fin core and thereby exposing the fin core;
• forming a thermal oxide on the epitaxial shell and the fin core that consumes a portion of the epitaxial shell and the fin core;
• removing the thermal oxide to form a recessed region wherein the epitaxial shell and the fin core are recessed in the nitride material;
• growing an epitaxial layer on the epitaxial shell and the fin core in the recessed region, wherein the epitaxial layer comprises a semiconductor material selected from the group consisting of silicon, silicon germanium and silicon carbon.