| 摘要 |
PURPOSE:To allow an element isolation region and capacitor grooves to be formed by self-alignment for the prevention of defects attributable to mask displacement by a method wherein a thick oxide film and semiconductor substrate is subjected to etching with an oxidation-resistant film serving as a mask for the formation of a groove, the groove is filled with insulating material, and then the semiconductor substrate is subjected to etching with an element isolation region and photoresist serving as a mask for the formation of capacitor grooves. CONSTITUTION:On a thermal oxide film 24 grown on a silicon substrate 23 in a process of thermal oxidation, a polycrystalline silicon film 25, silicon nitride film 26, and an oxide film 27 are deposited, in that order. A thick oxide film 29 is formed in an opening 28, and then etching is accomplished for the formation of a trench 30 to serve as an element isolating region. Next, the oxide film 27 is totally covered by a CVD-SiO2 film 31, and the exposed polycrystalline silicon film 25 is removed by etching. A process follows wherein a photoresist pattern 33 is formed on a thermal oxide film 24, to be selectively etched for the formation of grooves 34a and 34b for a trench capacitor. Diffusion layers 36a and 36b of the opposite conductivity type are selectively formed on the silicon substrate 23 and, thereon, thermal oxide films 37a and 37b are formed. Patterning follows for the formation of a capacitor electrode 38. |
