| 摘要 |
PURPOSE:To reduce simultaneously the input capacitance and the feedback capacitance, by forming a gate insulating film in the manner in which the film is thin on an epitaxial layer and thick on a channel forming region. CONSTITUTION:An input capacitance decreases accordingly as the thickness of a gate insulating film increases, and on the contrary, a feedback capacitance increases according as the thickness of the gate insulating film increases. Therefore, the gate insulating film is formed in the manner in which the film is thin on an epitaxial layer and thick on a channel forming region. For example, the gate insulating film of a part where a gate electrode 4 and an N-type epitaxial layer 2 face each other is thin and has a thickness of 400Angstrom . On the contrary, the gate insulating film of a part where the gate electrode 4 and a P-type channel forming region 5 face each other is thick and has a thickness of 400+600=1000Angstrom . Thereby, both the input capacitance and the feedback capacitance are reduced. |
