| 摘要 |
PURPOSE:To prevent impurities from diffusing in a metallic silicide film even if the heat treatment in after process is performed, by depositing excessive silicon in the silicide crystal grain boundary in a metallic silicide film, and making the diffusion path of impurities in this crystal grain boundary discontinuous. CONSTITUTION:This semiconductor device is equipped with an n-well 2 made in a p-type silicon substrate 1 and element isolating regions 3 made at specified intervals on the surface of the substrate 1. Moreover, a p<+>-type polysilicon film 9a or an n<+>-polysilicon film 9b is provided on the surface of the substrate 1, and a tungsten silicide film 12 is made on them. The tungsten silicide film 12 contains silicon excessively. This excessive silicon exists in a silicide crystal grain boundary, and it makes the interface between the fellow WSi2 crystals in the tungsten silicide film 12 being the diffusion path of n-type and p-type impurities discontinuous. Hereby, even if heat treatment is performed, the impurities never diffuse sideways in the tungsten silicide film 12. |
