| 摘要 |
PURPOSE:To prevent the generation of currents by a parasitic MOS transistor by obviating the formation of a path, through which currents are easy to flow to the side surface of an element section from the surface, without adding an impurity to the side surface. CONSTITUTION:Recessed sections 22 are formed to a p type Si substrate 21, an SiO2 thin-film 24 and a p type poly Si layer 25 are superposed, the film 24 is exposed onto a projecting section 23 through reactive ion etching, poly Si 26 is left on the side surface, and the surface is coated with SiO2 27. SiO2 28 is left in the recessed sections 22 through an etch-back. A first gate electrode 291 in MoSi extending on the layers 26, 28 is manufactured. The layer 26 of the side surface functions as a second gate electrode 292. n<+> Layers 31, 32 are formed to the element section 23 while using the electrodes 291, 292 as masks, the surface is coated with SiO2 33, and electrodes 351, 352 are formed. Since a work function of the electrode 292 to the Si substrate 21 is larger than that of the electrode 291, Vth of a parasitic MOS element generated on the longitudinal side surface of the electrode 291 of the n<+> layers 31, 32 can be made higher than that of the element of the surface, and a current increase by the parasitic element can be prevented. |
