Patent ID: 7071504
Filing Date: 2006-07-04
Classification: H01L

Abstract:
1. A thin film transistor device, comprising: a substrate; and a thin film transistor that has a semiconductor film formed above said substrate and a gate electrode intersecting said semiconductor film, said semiconductor film having a channel region overlapping said gate electrode and p-type impurities introduced into said channel region for controlling the threshold value, and a pair of high-concentration impurity regions, which are a source/drain, sandwiching said channel region, wherein an edge portion of said semiconductor film in a region that said gate electrode overlaps is taper-shaped, and wherein, in said channel region, the volume density of said p-type impurities in the taper-shaped section of said semiconductor film is twice to five times the volume density of said p-type impurities in a rest section of said semiconductor film.