| 摘要 |
PURPOSE:To increase dielectric strength by forming the insulator layer having the curved plane at the bottom of the groove in an MOS capacitor having a V- shaped groove structure. CONSTITUTION:After forming a field oxide film 32, a resistor mask 33 is formed followed by taper etching of a substrate 31 to form a groove 34. Next, a p<+> layer 35 and an n<+> layer 36 are formed on the side walls of the groove 34, after which the mask 33 is removed and an SiO2 film 37 is deposited over the whole surface. After that, etching is done to leave the SiO2 film 37 selectively on the tip portion at the bottom of the groove and the dielectric strength of this portion is increased. Then a gate oxide film 38 is formed by thermal oxidation and nextly a gate electrode 39 is formed. |
