| 摘要 |
PURPOSE:To form a TFT suitable for large scale integration by a method wherein the source, the drain, and the channel region of a MOS type transistor are provided inside a recess provided to a gate electrode, and the gate electrode is located above a channel section. CONSTITUTION:A silicon oxide film 103 is formed on all the surface of a semiconductor substrate 101, then a polysilicon film is formed thereon, BF<+>2 ions are implanted, and a gate electrode 103 of a MOS-type transistor is formed by anisotropic etching. A recess is provided to the gate electrode 103. Then, a silicon oxide film 104, a polysilicon film is formed thereon, and then BF2 ions are implanted for the formation of a source, a drain, and a channel region. In succession, a region 105 for source, drain and channel of a TFT is formed in the recess of the gate electrode. Then, a silicon oxide film 106 is formed on all the surface, a polysilicon film is formed thereon, BF2 ions are implanted, and a gate electrode 107 of a MOS-type transistor is formed of polysilicon film. By this setup, a semiconductor device is formed into a double-gate structure, in which flatness is improved to enhance degree of integration. |
