| 摘要 |
PURPOSE:To improve memory holding capability and yield in manufacture by forming an insulating film under a gate in double structure consisting of polyimide/SiO2, a film thickness ratio thereof is a specific value or more. CONSTITUTION:P<+> type source 11 and drain 12 are formed into the predetermined region of an N type semiconductor substrate 10 at a regular interval. A SiO2 film 13 is formed onto the source 11 and the drain 12 and a channel region between the source and the drain, and a polyimide film 14 is formed onto the film 13. The insulating film 15 is formed by the double structure of these film 13 and film 14. A gate electrode 16 is shaped onto the film 15. The film thickness ratio of the film 14/film 13 is set to 0.3 or more so that the uniformity of threshold voltage is ensured. Accordingly, excellent memory holding capability is obtained, and thickness can be thickened, thus easily controlling film thickness, then improving yield in manufacture. |
