Nonvolatile semiconductor memory device and manufacturing method thereof

A method of manufacturing a nonvolatile semiconductor memory device, the method comprising the steps of:

• forming a plurality of device isolation regions on a semiconductor substrate;
• forming a gate insulating layer on the entire surface of the semiconductor substrate;
• forming a floating gate electrode material on the entire surface of the resulting material;
• forming an anti-reflection layer on the floating gate electrode material;
• forming a photoresist pattern on the floating gate electrode material so that a portion of the floating gate electrode material overlying the device isolation region is exposed;
• performing a first etch on the floating gate electrode material to a depth, using the photoresist pattern as an etching mask;
• removing the photoresist pattern;
• forming a spacer material on the resulting material;
• etching back the spacer material to form spacers on sidewalls of the floating gate electrode material undergoing the first etch;
• and
• performing a second etch on the floating gate electrode material so that the floating gate electrode material is separated, using the residual anti-reflection layer and the spacers as an etching mask.

A method of manufacturing a nonvolatile semiconductor memory device, the method comprising the steps of:

• forming a plurality of device isolation regions on a semiconductor substrate;
• forming a gate insulating layer on the entire surface of the semiconductor substrate;
• forming a floating gate electrode material on the entire surface of the resulting material;
• forming an anti-reflection layer on the floating gate electrode material;
• forming a photoresist pattern on the floating gate electrode material so that a portion of the floating gate electrode material overlying the device isolation region is exposed;
• performing a first etch on the floating gate electrode material to a depth, using the photoresist pattern as an etching mask;
• removing the photoresist pattern;
• forming a conductive material on the entire surface of the resulting material;
• and
• performing a second etch by etching back the conductive material and the underlying floating gate electrode material to separate the floating gate electrode material from one another.