In {HEAD ~ embodiments}, {TAIL ~ an insulating layer} is formed at a lower portion of a channel area 
In { HEAD ~ embodiments } , { TAIL ~ an insulating layer } is formed at a lower portion of a channel area
OTH HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH