Method of manufacturing semiconductor device employing oxide sidewalls

Claim 1

A method of manufacturing a semiconductor NAND device by using a resist mask for photolithography, comprising the steps of: providing a semiconductor substrate coated with a tunneling oxide film and a NAND control gate structure including a first control gate layer, an intervening insulating film and a second control gate layer, providing a mask in which a plurality of lines with a desired width are arranged in parallel with intervening spaces on the control gate structure, forming a continuous CVD oxide film on the mask lines and on the control gate structure in the intervening spaces between the mask lines, removing a selected thickness of the oxide film by an anisotropic etching so that sidewalls of said oxide film are left on the side faces of the mask lines to reduce the width of the intervening spaces, etching to remove the portions of the first and second control gate layers and the intervening insulating layer in the spaces between the sidewalls, injecting ions into the Si wafer with self align through the intervening spaces between lines with the mask line sidewalls, wherein the resulting NAND control gate line width is greater than the width of the intervening spaces, and forming a bit line array extending transversely across the NAND control gate lines.

Claim 2

A method of manufacturing a semiconductor NAND device by using a resist mask for photolithography, comprising the steps of: providing a semiconductor substrate coated with a tunneling oxide film and a NAND control gate structure including a first control gate layer, an intervening insulating film and a second control gate layer, providing a mask in which a plurality of lines with a desired width are arranged in parallel with intervening spaces on the control gate structure, forming a continuous CVD oxide film on the mask lines and on the control gate structure in the intervening spaces between the mask lines, removing a selected thickness of the oxide film by an anisotropic etching so that sidewalls of said oxide film are left on the side faces of the mask lines to reduce the width of the intervening spaces, etching to remove the portions of the first and second control gate layers and the intervening insulating layer in the spaces between the sidewalls, injecting ions into the Si wafer with self align through the intervening spaces between lines with the mask line sidewalls, wherein the resulting NAND control gate line width is greater than the width of the intervening spaces, and forming a bit line array extending transversely across the NAND control gate lines.