| 摘要 |
PURPOSE:To improve the operating speed and to reduce a short channel effect of an MIS transistor by performing the activations of a polysilicon layer and source/drain in separate steps to form the transistor having a low resistance polysilicon gate, polysilicon wirings and shallow source/drain. CONSTITUTION:A polysilicon film 3 is formed on a gate oxide film 2 formed on a P-type substrate 1, heat treated at high temperature in a short time, an N-type impurity in the polysilicon 4 is sufficiently electrically activated, and the crystal grain size of the polysilicon is increased, thereby reducing the resistance. Then, a polysilicon gate 7 is formed, with the gate 7 as a mask an implanted layer 5 is formed by ion implantation in the substrate 1. Then, an intermediate insulation film 10 made, for example, of SiO2 is formed on the gate 7 and the film 2, heat treated at low temperature for a short time to electrically activate the layer 5, thereby forming source/drain 6. The depth of the source/drain 6 is formed sufficiently shallow by the low temperature heat treatment to form a transistor which is suppressed in the short-channel effect and has high performance.
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