| 摘要 |
PURPOSE:To increase the contact resistance for preventing the deterioration of a device, by providing first polycrystalline semiconductor layers within contact holes such that the contact holes are not completely filled with these layers, and selectively depositing second polycrystalline semiconductor layers on the first layers so as to be embedded within the contact holes. CONSTITUTION:A DPSG layer 2 as an insulation layer is adhered on the whole surface of a semiconductor substrate 1. The semiconductor substrate 1 is provided with a contact hole 3, while a polysilicon layer 1' is provided with a contact hole 3'. The contact holes 3 and 3' are filled by the CVD process with a polysilicon layer 4. This polysilicon layer 4 as a first polycrystalline semiconductor layer is also adhered on the whole surface of the substrate. The CVD deposition of the polysilicon is performed under the conditions that monosilane as a reactive gas is reduced in pressure and pyrolized at a temperature of 600 deg.C. Subsequently, the polysilicon layer 4 is dry etched until the surface of the DPSG layer 2 is exposed, and further etched until a thin layer of the polysilicon 4 is left within the contact holes 3 and 3'. Selective epitaxy is performed so that the polycrystalline silicon is caused to grow to fill both the contact holes to form polysilicon layers 5 and 5' as second polycrystalline semiconductor layers. |
