Patent ID: 8304779
Filing Date: 2012-11-06
Classification: H01L

Abstract:
1. A thin film transistor comprising: a gate insulating film formed over a gate electrode; a microcrystalline semiconductor film including an impurity element which serves as a donor, which is formed over the gate insulating film; a pair of buffer layers formed over the microcrystalline semiconductor film including the impurity element which serves as the donor; a pair of semiconductor films including an impurity element imparting one conductivity type, which are formed over the pair of buffer layers; and wirings formed over the pair of semiconductor films including the impurity element imparting one conductivity type, wherein the pair of buffer layers are spaced from each other, and wherein a concentration of the impurity element which serves as the donor in the microcrystalline semiconductor film is decreased from the gate insulating film side toward the pair of buffer layers with a slope of from 5 to 120 nm/dec.