| 摘要 |
PROBLEM TO BE SOLVED: To prevent a damage to a substrate or a residue of etching in the process of forming a memory cell region, by performing patterning process for element isolating region in a peripheral circuit region after the process of patterning the element isolating region of a memory cell region. SOLUTION: An oxide silicon film 102 is formed on the surface of a silicon substrate doped with P-type impurities. The film is subjected to patterning and an element isolating oxide film is formed. Net, an oxide silicon film 102 is formed and then a gate oxide film 104 is formed, thereby forming a polycrystalline silicon film 105. Next, a polycrystalline silicon film 105 is patterned. At this time, the periphery is covered with an oxide silicon film 102 so that substrate damage or etching reside in the peripheral region is eliminated. Next, oxide silicon film 106, polycrystal line silicon film 107 and oxide silicon film 108 are sequentially formed. And patterning is performed sequentially for the oxide silicon film 108 and polycrystalline silicon film by self-alignment. |
