| 摘要 |
PURPOSE:To increase the reliability of the semiconductor device by forming a source and a drain from doped polysilicon smoothed on the surface with a laser when forming an Si gate MOSFET, using the polysilicon as electrodes, flattening the surface and preventing the disconnection of the metal wires. CONSTITUTION:A field oxide film 12, a gate oxide film 13 having holes 14a, 14b and a phosphorus-doped polycrystalline silicon 15 are formed on a P type Si substrate 11, laser light rays are irradiated thereto, and the surfaces are smoothed. A thin oxide film 16, a gate region formed thereon, silicon nitride films 17, 18a, 18b covered on the contact regions 14a, 14b are formed. They are then heat treated to convert the polycrystalline silicon into silicon oxide film, and the phosphorus reaches the substrate 11, and source and drain diffused layers 20a, 20b are formed. The polycrystalline silicon is retained on the region covered with the nitride film, and a gate electrode 22, and contact polycrystalline silicon films 21a, 21b are formed. Thus, the FET having shallow source and drain diffused layers can be formed. |
