| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device in which there is no limit with respect to film thickness, and reducing the gate electrode thickness is extremely easy and conductive types are differentiated by only one-time patterning, when a deposited polycrystalline silicon film is doped. SOLUTION: In this manufacturing method, after a gate insulating film 14 is formed on a semiconductor substrate 11, for example, a polycrystalline silicon film 15 of a p-conductive type containing B(boron), which is thinner than a conventional one, is deposited. By mounting a mask on this film, exposing the semiconductor substrate to a gas containing a compound of As or P(phosphate), which is an atom of n-conductive type, and subjecting it to heat treatment, the region which is not covered with the mask in the polysilicon film 15b is changed to n-type and the concentration of B contained in the region changed into an n-type is reduced by outward diffusion. Since there is no limit in making the polycrystalline silicon film thinner with respect to either the n-type or p-type, reducing the thickness of gate electrodes is made extremely easy.
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