| 摘要 |
PURPOSE:To prevent a source and a drain from being disconnected therebetween in a thin film transistor by providing a second insulating film made of a material having etching characteristics of large selection ratio with respect to a first insulating film on the film to become a gate insulating film. CONSTITUTION:After a polycrystalline silicon film is formed on an oxide film 102 formed by thermally oxidizing a silicon substrate 101, a polycrystalline silicon film 103 is formed by photoetching, and a gate oxide film 104 is formed by thermally oxidizing. Then, a source, drain region 105 and a channel region 106 are formed in the film 103 by ion implanting. Then, a silicon nitride film 107 is formed, a pSG film is formed as an interlayer insulating film 108, and thermally annealed. Then, a gate region 201 and a contact region 202 of the film 108 are removed, and the film 107 is removed with a hot phosphoric acid as an etchant. Then, the region 104 of the region 202 is removed, and wirings and a passivation film 110 of aluminum electrode 109 are formed. Thus, the gate can be oxidized before adding an impurity to the source, drain. |
