| 摘要 |
PURPOSE:To improve a patterning precision by a method wherein, after a groove is dug on a semiconductor substrate, oxide masks for the surface other than the grooved region and a selective oxide film to be used for isolation on the sidewall surface of the groove are simultaneously patterned. CONSTITUTION:An oxide mask 2 is formed on the whole surface of a semiconductor substrate 1 and thereafter, an Si oxide film 5 is formed and this is subjected to deep groove etching. Then, after an Si nitride film 2 is formed on the whole surface, an Si oxide film 7 is formed on the whole surface and this is etched. Subsequently, the oxide mask 2 is removed to perform an entire surface etching, the whole surface of the Si oxide film 3 is etched and the oxide mask 2 only on the bottom surface of a groove is removed. Subsequently, the Si nitride film 2 is patterned simultaneously with the removal via a photoengraving process, wherein a multilayer resist is used, and an isolation of the surface other the grooved region on the substrate and an isolation oxide film on the sidewall surface of the groove are formed.
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