PURPOSE: To obtain a thin film transistor (TFT) having an a-Si film, with which a TFT active matrix of large area can be formed easily, as a semiconductor film by a method wherein the a-Si film with which a channel will be formed is formed in two-layer structure, and the activation energy of the a-Si film on the side of a gate insulating film is made smaller than that of the a-Si film located on the opposite side.
CONSTITUTION: A gate electrode 4, an insulating film 6, an amorphous semiconductor thin film (a-Si film) 50 having silicon as the main ingredient, a source electrode 2, and a drain electrode 3 are arranged on a semiconductor 1 having at least an insulated surface. The a-Si film 50 of the above-mentioned thin film transistor is formed in double-layer structure, and the activation energy of conductivity of the a-Si film 51 located on the side where the film 51 comes in contact with an insulating film 6 is made smaller than that of the other a-Si film 52. For example, the content of H2 of the a-Si film 51 on the side where it comes in contact with the gate insulating film 6 is made smaller than that of the a-Si film 52 on the reverse side of the gate insulating film 6, and the activation energy is formed at 0.6eV. Also, the content of H2 of the a-Si film 52 located on the reverse side of the gate insulating film 6 is made greater than that of the a-Si film 51 located on the side where it comes in contact with the gate insulating film 6, and the activation energy is formed at 0.8eV.
YORITOMI YOSHIFUMI
KENMOCHI AKIHIRO
KOSHIMO TOSHIYUKI
SUNAHARA KAZUO
