| 摘要 |
PURPOSE:To enable to prevent the reduction of the capacitor area by inhibition of the lateral intrusion of a selective oxide film at the cell section by a method wherein a double-layer film of an Si nitride film and an Si oxide film used as a mask is made as an insulation film under a capacitor gate, and oxidation is carried out in the state of leading this double-layer film. CONSTITUTION:An oxide film 2 and a nitride film 3 are formed on a p type Si substrate 1, the inter-element nitride film 3 and the oxide film 2 being removed by etching, and a p type impurity, e.g., boron being then introduced into the Si substrate in the inter-element region. Next, when a field oxide film 7 is formed in the inter-element insulation section by oxidation, a parasitic channel prevention layer 6 produced by the p type impurity is formed under the oxide film 7. A polycrystalline Si film is adhered, and a conductive impurity is doped, and the capacitor gate 8 is formed through the process of photoetching, next oxidation is performed. Thereby, the thickness of the field oxide film in the part other than the cell capacitor increases, and at the same time an oxide film 9 grows in the surface of the capacitor gate, and accordingly excellent inter-element and interlayer insulation are accomplished. |
