摘要 |
A gate insulating film composed of silicon oxide and a floating gate electrode composed of polysilicon are formed sequentially on a P-type silicon substrate. A capacitance insulating film composed of silicon oxide and a control gate electrode composed of polysilicon are formed on the floating gate electrode. First spacer films, each composed of silicon oxide and formed over the respective side faces of individual components, and second spacer films, each composed of silicon nitride and formed on the respective first spacer films, are also provided. Even when a high-temperature heat treatment is performed in an oxidizing atmosphere, oxygen is prevented from being supplied to both end portions of the capacitance insulating film and the control gate electrode, which suppresses an increase in thickness of the capacitance insulating film at both end portions thereof.
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