| 摘要 |
PURPOSE:To upgrade mobility of a TFT and to suppress fluctuation in a threshold voltage, by oxidizing a surface of an SiN film which is an insulating film for a gate electrode and then forming an a-Si film of a semiconductor film. CONSTITUTION:A gate electrode 12, a gate electrode's insulating film 13 composed of an SiN film 13a and an SiOX film 13b, a semiconductor film 14 made of a-Si, an n-type a-Si 14' doped with phosphorus, a drain electrode 15 made of Cr 17 and Al 18, and a source electrode 6 made of Cr 15 and Al 18 are disposed serially on an insulating substrate 11 made of a glass plate or the like so that a thin film transistor TFT is formed. Said N<+> a-Si film 14' is formed to decrease a contact resistance of the electrode. Silicon dioxide of stoichiometric composition is not necessarily used in the SiOX film, but it is desirable that hydrogen and nitrogen are contained and its composition is defined with a range of 1.95<=x<=2.35. It is also desirable that only a surface layer of the SiN film is made of SiOX and its thickness is so at least 1nm to be a half or less of the SiN film. |
