| 摘要 |
PURPOSE:For increasing a capacity section in capacitance without increasing the size of cell surface, to provide in a semiconductor substrate a recess contacting with a source and drain range and a source range through the medium of insulating film. CONSTITUTION:An N-type source range 3 and a drain range 4 are diffusedly formed on an P-type Si substrate 1, and SiO2 film 10 is formed on the whole surface of said substrate 1. Next, plasma etching is made by using the mask of photo resist film 11 to form a deep recess 12 in said substrate 1 with the side faces of said range 3 exposed. Thereafter, said film 11 is removed. SiO2 film 2 is deposited on the exposed surface of said recess 12 and combined with said film 10, said film 10 located between said ranges 3 and 4 is decreased in thickness into a thin film 5, and a gate electrode 6 is fitted on said film 5. Next, an opening is provided in said film 10, a drain electrode 7 is fitted to connect with said range 4, and a polycrystalline Si capacity section electrode 8 is buried in said recess 12. Thereafter, thick film SiO2 film 13 is formed between said electrodes 6, 7 and 8, and electrodes 6', 7' and 8' are made by increasing said electrodes 6, 7 and 8 in volume. |
