Semiconductor device including epitaxially formed buried channel region

A semiconductor device, comprising:

• at least one semiconductor fin on an upper surface of a substrate that includes a buried insulator layer, the at least one semiconductor fin including a fin body composed entirely of a first semiconductor material that extends from the upper surface of the buried insulator layer to an upper surface of the at least one semiconductor fin, and including a dual-channel region interposed between opposing source/drain regions;
• and
• a gate stack on the upper surface of the substrate and wrapping around sidewalls and an upper surface of only the channel region, the gate stack including a first gate spacer interposed between a first source/drain region of the opposing source/drain regions and the dual-channel region, and a second gate spacer interposed between a second source/drain region of the opposing source/drain regions,
• wherein the dual channel region comprises a portion of the fin body to define a buried channel portion and a surface channel portion on the buried channel portion that completely surrounds sidewalls and the upper surface of the buried channel portion, and
• wherein the surface channel portion does not extend beyond inner sidewalls of the first and second gate spacers.