| 摘要 |
<p>PROBLEM TO BE SOLVED: To stabilize element characteristics and to inexpensively achieve mass production by forming a reaction preventing film preventing that a gate electrode reacts with an element in a gate insulating film between the gate electrode and the gage insulating film. SOLUTION: A reaction preventing film 17 is a part on a gate insulating film 16 and is formed in a position corresponding to a channel area 13. The reaction preventing film 17 prevents elements in the gate insulating film 16, especially, oxygen ions and hydrogen ions in the gate insulating film 16 react with a gate electrode 18, for example. In polysilicon TFT, dopant is doped and it is thermally treated at the temperature of not lower than 500 deg.C. Thus, polysilicon TFT where dopant is electrically and sufficiently activated and the crystallinity of polysilicon is satisfactory, namely, a characteristic is satisfactory can be obtained. Since it can be manufactured by using an ion doping device where the mass separation of ion species is not conducted.</p> |
