MANUFACTURE OF SEMICONDUCTOR DEVICE

摘要

PURPOSE:To decrease the effect exerted to upper element regions during the formation of a capacitance region, by surrounding an MOS transistor forming region near the surface of a semiconductor substrate with an oxide film or the like before forming capacities within deep grooves. CONSTITUTION:A resist mask 2 is deposited on a PSi substrate 1 and shallow grooves are formed on the substrate 1 by etching the same. An n<+> region 4 and a p<+> region 5 are provided in the grooves. An SiO2 film 6 is then deposited on the whole surface and is dry etched so that oxidized SiO2 films 7 are left only on the side faces of the grooves. The grooves in the substrate are further etched to form deep grooves. N<+> regions 8 are provided on the side faces of the grooves while p<+> regions 9 are provided on the bottom thereof. Finally, after the grooves are filled with polysilicon 15, 1 gate electrode 12, a source 11 and a drain 10 are formed.