Patent ID: 7374995
Filing Date: 2008-05-20
Classification: H01L

Abstract:
1. A method of manufacturing a nonvolatile semiconductor memory device comprising: sequentially depositing a first gate insulation film and a first conductive layer on a semiconductor substrate; forming a floating gate of a memory cell by patterning the first conductive layer; forming source and drain regions of the memory cell in the semiconductor substrate; depositing an inter-gate insulation film on the entire surface of the resultant structure; exposing the semiconductor substrate by removing the inter-gate insulation film and the first gate insulation film in and around a region in which to form a selection gate of a selection transistor for selecting the memory cell; forming a second gate insulation film on the exposed surface of the semiconductor substrate; forming first and second control gates of the memory cell which are arranged on both sides of the floating gate with the inter-gate insulation film interposed and a selection gate, by patterning a second conductive layer after depositing and flattening the second conductive layer on the entire surface of the resultant structure; and forming source and drain regions of the selection transistor in the semiconductor substrate so that one of the source and drain regions is integral with one of the source and drain regions of the memory cell.