| 摘要 |
PURPOSE:To prevent an N-channel polycrystal silicon thin film transistor from shifting abnormally in the direction of depletion, by applying a selective channel doping with low concentration boron to the channel part of an N-channel polycrystal silicon thin film transistor. CONSTITUTION:A boron-doped region 1-8 and a phoshorus-doped region 1-9 are formed by applying a gate electrode 1-7 to a mask, and implanting ions of boron or phosphorus into necessary parts. In this manner, a P-channel polycrystal silicon thin film transistor 1-10 and an N-channel polycrystal silicon thin film transistor 1-11 which is subjected to a channel doping with low concentration boron are formed. Next, an interlayer insulating film 1-12 is formed. The boron-doped region 1-8 and the phosphorus-doped region 1-9 are subjected to a thermal treatment for activation, and then subjected to a hydrogen plasma treatment or a hydrogen ion implantation treatment. Thereby, the problem that the P-channel polycrystal silicon thin film transistor shifts largely in the direction of enhancement can be solved. |
