| 摘要 |
PURPOSE:To reduce the parasitic capacity of the semiconductor device upon reduction of the size of the device by forming stereoscopically an element region when forming an SOS-type MOS transistor. CONSTITUTION:An N<+>-type layer, a P-type layer, a P<->-type layer and an N<+>-type layer are laminated to form them in a plane (100) while additionally adjusting the impurity in Si on a sapphire substrate 2 in epitaxial grown. Then, in order to obtain a transistor forming surface, unnecessary portion is etched with an etching solution of KOH group having much larger etchig rate for the etching rate for the plate (111) than the etching rate for the plane (100) of the surface 18a of the epitaxial layer to form a trapezoil having an oblique surface (111) at an angle of 57 deg. with respect to the plane (100). Then, a gate oxide film 4 is formed around the N<+>PN<+>- layer forming the trapezoil, a polycrystalline Si is coated thereon, is patterned, as a gate electrode G, a PSG film 24 is then coated thereon, openings are perforated thereat, and source and drain electrode wires 20, 22 are mounted therethrough. |
