| 摘要 |
PURPOSE:To provide an E/D mode MOSIC having a multilayer electrode constuction by isolating a silicon substrate by a thick field oxide film, providing a thin gate oxide film thereat as an enhancemenet type element region, and implanting ion to the adjacent region thereto to thereby form a depletion type element region. CONSTITUTION:A plurality of thick field oxide films 2 are formed on a p-type silicon substrate 1, films 3 becoming thin gate oxide films are coated therebetween, and ion is implanted into the substrate 1 under the film 3 to thereby form a p-type region 31 for controlling the threshold voltage of an enhancement type element. Then, the film 3 on the region 31 is selectively retained, a polycrystalline silicon gate electrode 4 is formed on the film 3, and a polycrystalline silicon wires 4' are formed on the film 2. Then, with the wires 4' as mask ion is implanted to thereby alter the portion under the region 31 into an n-channel layer 32 and the layer 32 of the other region interposed with the film 2 into a depletion type element region. Simultaneously, n-type source and drain regions 33 and 34 are formed in the enhancement type element region, and source and drain regions 35 and 36 are formed in the depletion type element region. |
