said sidewall surface of said main part including a sharply pointed tip end part defined by two crystal surfaces and located at a lower side of {HEAD ~ an interface} between said gate insulation film and said {TAIL ~ silicon substrate} 
said sidewall surface of said main part including a sharply pointed tip end part defined by two crystal surfaces and located at a lower side of { HEAD ~ an interface } between said gate insulation film and said { TAIL ~ silicon substrate }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL