Patent ID: 8530899

Claim:
A thin film transistor, comprising: a gate electrode formed on a substrate; an insulating layer formed so as to cover said gate electrode; a microcrystalline amorphous silicon layer and an amorphous silicon layer that are formed on said insulating layer; a semiconductor layer containing an impurity formed on said amorphous silicon layer; and a source electrode and a drain electrode that are formed on said semiconductor layer containing an impurity, wherein said microcrystalline amorphous silicon layer and said semiconductor layer containing an impurity are connected to each other through said amorphous silicon layer without being in direct contact with each other, wherein said semiconductor layer containing the impurity includes a first contact portion that is in contact with said source electrode and a second contact portion that is in contact with said drain electrode, and wherein when viewed in a cross-section that is normal to a plane of said substrate and that cuts across said source electrode and said drain electrode, a width of said microcrystalline amorphous silicon layer is narrower than a width of a space between said first contact portion and said second contact portion.