SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF, NONVOLATILE SEMICONDUCTOR MEMORY DEVICE AND MANUFACTURING METHOD THEREOF, AND ELECTRONIC DEVICE HAVING NONVOLATILE SEMICONDUCTOR MEMORY DEVICE

摘要

PURPOSE: A semiconductor device and a manufacturing method thereof, a nonvolatile semiconductor memory device and a manufacturing method thereof, and an electronic device having the nonvolatile semiconductor memory device are provided to obtain high yield in devices having different oxide film thicknesses. CONSTITUTION: In a state where gate insulating films of different film thicknesses are formed in processes hereafter by placing a step in height between regions that form gate insulating films of different thicknesses on the surface of a semiconductor substrate(101), the heights of the surfaces of the gate insulating films(110,111) become evenness. Consequently, the upper surfaces of the gate insulating films(110,111), which become underlying when a gate electrode is formed, are planarized while having different oxide films. The silicon oxide film(115) is excessively scraped off by progressing of etchant to an interface that is caused from the difference of film thickness of the conventional gate insulating films, and then the initial failure of the gate insulating film is generated and a lifetime thereof is reduced.