Patent ID: 11011472

Abstract:
The present invention discloses a self-aligned register structure for base polysilicon and a preparation method thereof. The self-aligned register structure comprises a silicon substrate having a partially oxidized region of SiO2 medium, a SiO2 medium protective layer is arranged at a center above the silicon substrate, base polysilicon layers are located at left and right sides of the SiO2 medium protective layer, the adjacent base polysilicon layers are symmetrical to the SiO2 medium protective layer at equal spacing, and the spacing is equal to a thickness of the base polysilicon layer. The self-aligned register structure for base polysilicon of the present invention meets an extremely high register requirement, guarantees the uniformity of electric parameters of devices, and eliminates physical or chemical damage to an intrinsic region when etching a surface of the silicon substrate during the forming of the base polysilicon, thus reducing the capacitance and enhancing the product yield; and meanwhile, the preparation method is simple, convenient, low in cost, and short in time.