US Patent 7678649 Semiconductor device and manufacturing method thereof

To provide a nonvolatile memory having an excellent data holding property and a technique for manufacturing the memory, a polycrystalline silicon film 7 and an insulating film 8 are sequentially stacked on a gate insulating film 6, then the polycrystalline silicon film 7 and the insulating film 8 are patterned to form gate electrodes 7A, 7B, and then sidewall spacers 12 including a silicon oxide film are formed on sidewalls of the gate electrodes 7A, 7B. After that, a silicon nitride film 19 is deposited on a substrate 1 by a plasma enhanced CVD process so that the gate electrodes 7A, 7B are not directly contacted to the silicon nitride film 19.