| 摘要 |
PURPOSE:To unnecessitate alignment margins by a method wherein grooves for element-isolating regions and those for capacitor parts are simultaneously opened by RIE or the like. CONSTITUTION:An SiO2 film 22 is deposited on an Si substrate 21 and then etched by RIE, and a groove 23 and capacitor grooves 24... are formed by etching the substrate 21 by using the mask of the SiO2 film 22. After removal of this film 22, a gate oxide film 25 is formed and phosphorus is diffused to a polycrystalline Si layer 26 which has been formed over the whole surface. Next, the layer 26 is wholly etched by RIE, thus leaving polycrystalline Si layers 27 and 28. After the film 25 is successively etched away, an oxide film 29 is formed. At this time, an oxide film 30 is formed on the layer 27, and oxide films 31 on the layers 28.... Windows 33... are formed at the corresponding parts of the oxide films 31..., and a polycrystalline Si layer 34 is deposited over the whole surface. When phosphorus is diffused thereto, the layers 28... are connected to the layer 34 via windows 33. This manner can avoid the overetching of the oxide films of element-isolating regions. |
