Patent ID: 7038283

Claim:
A thin film transistor device, comprising: a high-voltage driven thin film transistor formed on a substrate; and a low-voltage driven thin film transistor formed on said substrate, wherein said low-voltage driven thin film transistor includes: a first semiconductor film having a first pair of high concentration impurity regions formed so as to sandwich a first channel region; a first gate insulating film formed on said first channel region of said first semiconductor film, and constituted by a first insulating film only; and a first gate electrode formed on said first gate insulating film, and said high-voltage driven thin film transistor including: a second semiconductor film having a second pair of high concentration impurity regions formed so as to sandwich a second channel region, and low concentration impurity regions formed between said second pair of high concentration impurity regions and said second channel region; a second gate insulating film formed on said second channel region and said low concentration impurity regions, said second gate insulating film being formed to be thicker than said first gate insulating film and constituted by laminating said first insulating film and a second insulating film; and a second gate electrode formed on said second gate insulating film.