| 摘要 |
A method for manufacturing a nonvolatile semiconductor memory device having a memory cell array and peripheral circuit portion, includes the steps of forming a field oxide film (220) on a semiconductor substrate (110) so that an active region and an isolation region can be formed, forming a first dielectric layer (211) on the entire surface of the substrate, forming a first conductive layer (311) on the first dielectric layer (211), patterning the first conductive layer (311) so that a first conductive pattern (311a) can be formed in the memory cell array and in the peripheral circuit portion, forming a second dielectric layer (230) on the entire surface of the substrate, selectively etching the second dielectric layer (230), first conductive pattern (311a) and first dielectric layer (211) formed in the peripheral circuit portion thereby to expose the surface of the substrate in the peripheral circuit portion, forming a third dielectric layer (212) on the substrate of the exposed peripheral circuit portion and on the second dielectric layer (230) of the cell array, forming a second conductive layer (312) on the entire surface of the substrate, and patterning the second conductive layer (312), second dielectric layer (230), third dielectric layer (212) and first conductive layer (311) thereby to form a gate electrode (312a) in the peripheral circuit portion, a control gate (312b), a floating gate (311b) and an upper dielectric layer (230b) in the cell array, thus suppressing the reduction of the field oxide film and micro-pitting on the surface of the silicon. <IMAGE> |
