| 摘要 |
PURPOSE:To simplify processes, to reduce the stepped difference of a foundation in an Al wiring layer and to minimize disconnections by forming a region of low resistance and a region of high resistance in a polycrystalline silicon layer as one layer. CONSTITUTION:A polycrystalline silicon film 4 is grown, and phosphorus ions are implanted. A film 11 preventing the outward diffusion of an impurity is formed, only the surface of the polycrystalline silicon film as a gate electrode and a wiring region is coated, and others are removed. Low resistance is obtained through heat treatment in a polycrystalline silicon layer deposited at a low temperature just under the SiO2 film 11 because the activation of implanted phosphorus progresses and the recrystallization of polycrystalline Si advances. An N<+> type contact region 12 is formed in a substrate just under a contact window 7. On the other hand, phosphorus in polycrystalline silicon evaporates by outward diffusion through heating in a short time at a high temperature by infrared radiation and a high resistance layer is acquired in the polycrystalline silicon layer 4 in a region, on the surface thereof the SiO2 film 11 is not formed. |
