Design and fabrication of Tri-Gated FinFET

A Tn Gated Fin Field Effect Transistor is on of the many novel devices that may be replacing planar MOSFETs, by reducing short channel effects. The FinFET has emerged as one of the most promising double gate structures primarily because of its ease of manufacturing. There are still significant challenges to overcome it in order to make the process available commercially. The Tri-Gated FinFET is tri-gated meaning that the gate overlaps the top and the two sides of the FIN. Three dimensionally the gate depletes three surfaces of the FIN, which results in a higher drive current relative to a planar MOSFET. In order to reduce current crowding in the Fin corners, we have curved the corners using oxide etch back process. FinFETs has been built previously at Rochester Institute of Technology. We have designed and fabricated Tri-Gated FinFETs of various geometries. Electrical test showed poor performance of the devices. Proper scrutiny of the electrical results and the SEM micrographs allowed us to conclude that if LTO or Nitride is used as etch hard mask for silicon fin etch, electrical results closer to that of an ideal NMOS transistor could would be achieved