| 摘要 |
PURPOSE:To prevent side wall of a cell transistor from being affected by alkali metal pollution and problems such as data inversion from being produced by providing a non-volatile memory element with a cell transistor having doped oxide film to a transistor in LDD construction which was formed on the same substrate and to the side wall. CONSTITUTION:A field oxide film 102 for separating elements and the first gate oxide film 103 are formed on a p-type semiconductor substrate, a polycrystalline silicon layer is built up on the entire surface, which is subject to patterning, a gate electrode 104 is formed at a CPU part, a polycrystalline silicon layer 105 is left as it is without performing etching at an EPROM part, and the polycrystalline silicon layer 105 becomes a floating gate and a polycrystalline silicon layer 108 becomes a control gate at the EPROM part. After forming an oxide film for insulation is formed around a complex gate of the EPROM part, a phosphosilicate glass(PSG) 114 which is a silicon oxidation film doped with phosphorus is built up on the entire surface and is etched back to allow PSG layers 115, 116, 117, and 118 to remain only on the side wall of each gate electrode. |
