Patent ID: 7087963

Claim:
A thin film transistor comprising a semiconductor film, a first gate insulating film, a second gate insulating film and a gate electrode sequentially formed on one major surface of a substrate in that order, wherein said first gate insulating film covers said semiconductor film, said second gate insulating film is made of a material for supplying hydrogen to said semiconductor film, said second gate insulating film is integrally formed over said first gate insulating film, which covers said semiconductor film, said second gate insulating film has a smaller film thickness in a region not covered with said gate electrode than that in a region covered with said gate electrode, alone a channel length direction of a channel region of said thin film transistor formed in said semiconductor film, from an end position of said gate electrode covering said second gate insulating film; said second gate insulating film covers said first gate insulating film in said region not covered with said gate electrode in which said second gate insulating film has said smaller film thickness; and said second gate insulating film has a smaller film thickness from said end position of said gate electrode covering said second insulating film.