| 摘要 |
PURPOSE:To prevent substrate surface from damages and to enhance memory device reliability by a method wherein a part is removed of an SiO2 film formed on an Si substrate, an Si3N4 film and electrodeforming materials are provided whereby a capacity electrode is formed to cover the area with its SiO2 removed for the formation of an FET adjacent to the capacity-generating area. CONSTITUTION:A field oxide film 303 is formed on an Si substrate 301 and then provided with an opening. The opening is covered with a thin thermally oxidized film 305 and the entirety is covered with a doped poly-Si layer 306. A capacity- generating area is covered with a resist 307 and the thermally oxidized film 303 is exposed by reactive ion etching. The film 303 protects the Si substrate 301 from possible damages. A part of the remaining film 303 is replaced with a gate oxide film 308 whereon a gate electrode 309 and source/drain electrodes 310 are built for the formation of a switching FET. The device being thus constructed, a larger-capacity memory is ensured, leak is prevented of accumulated charges to be caused by poor gate insulation or abnormal leak currents, realizing improved yields and enhanced reliability. |
