摘要 |
In a method of manufacturing a nonvolatile semiconductor memory device, a first polysilicon conductive layer, which is formed in a peripheral circuit region on a semiconductor substrate with a third gate insulating film interposed therebetween, is patterned into the shape of a gate electrode. A gate bird's beak is formed below the gate electrode in the peripheral circuit region by means of a heat treatment in an oxidizing atmosphere. Subsequently, in a memory cell array region, the first polysilicon conductive layer and a second polysilicon conductive layer laminated thereabove are processed to obtain a stacked gate structure.
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