| 摘要 |
PURPOSE:To improve element density, by forming transistors in front of semiconductors on an insulating substrate and forming capacitors in the recessed parts of the insulating substrate. CONSTITUTION:While trenches are formed in one surface of a Si substrate 1 or the like, the first polycrystalline Si layer 2 is formed thereon, and every unit consisting of transistors and capacitors is isolated. Successively, an oxide film 3 is piled thereon and then the regions except capacitor parts are masked with a photoresist film 8. Then, after the oxide film 3 on the capacitor parts is then etched and removed, ion implantation of P is performed to reduce the resistance on the capacitor parts of the first polycrystalline Si layer 3 so that N<+> is formed. Successively, the capacitor insulating film 3 is formed on the whole surface and then the second polycrystalline Si layer 4 is grown as a plate electrode on the whole surface, with a photoresist layer 9 being piled thereon to form openings there. Furthermore, the second polycrystalline Si layer 4 is exposed to form a gate oxide film 16 and pile the third polycrystalline Si layer 10 as a gate electrode. Needless parts of the second polycrystalline Si layer 4 are then removed to perform ion implantation of donors into the first polycrystalline Si layer 2 so that source and drain regions are formed, and a SiO2 layer 5 with a pit line 6 piled is formed thereon. |
