| 摘要 |
PURPOSE: To form a shallow emitter junction without reducing the conductivity of a polysilicon emitter electrode, by doping the polysilicon of the emitter with two kinds of dopants. CONSTITUTION: A laminated structure of polysilicon layers 64 and 68 is doped in order to improve the connectivity of the structure throughout the entire structure, and to prepare dopants to be diffused into an emitter area from a intrinsic base area 61. Then, the layers 64 and 68 are doped with two kinds of dopants respectively having high and low diffusion coefficients in silicon. In this case, the depth and conductivity of the emitter required front eh structure can be optimized by independently adjusting the implanting conditions of arsenic and phosphorus. Then, a gate electrode 69g and an emitter electrode 69e are defined by patterning and etching the laminated layer. Therefore, a shallow emitter junction can be formed without reducing the conductivity of the polysilicon emitter electrode 69e.
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