Patent ID: 7375001

Claim:
A method of manufacturing a semiconductor device formed on an SOI substrate comprising a semiconductor support substrate, a buried insulation film formed on the semiconductor support substrate, and a silicon active layer formed on the buried insulation film, comprising the steps of: patterning the silicon active layer to form single-crystal silicon resistors; etching the silicon active layer and the buried insulation film to form an island-shape silicon active layer on an island-shape buried insulation film on the semiconductor support substrate to thereby form single-crystal silicon resistors; forming an insulation film to a thickness of 0.01 μm to 0.04 μm by thermal oxidation; depositing a first polycrystalline silicon to a thickness comparable to the depth from the silicon active layer to the semiconductor support substrate surface portion; etching the first polycrystalline silicon by anisotropic dry etching until the insulation film surface is exposed to form side spacers over sidewalls of step portions of the island-shape silicon active layer, the buried insulation film, and the semiconductor support substrate via the insulation film; implanting a dopant of a first conductivity type at 1×10 14 to 9×10 18 atoms/cm 3 into a whole or a first region of the single-crystal silicon resistors; implanting a dopant of a second conductivity type at 1×10 14 to 9×10 18 atoms/cm 3 into a second region of the single-crystal silicon resistors; forming a gate insulation film on the single-crystal silicon resistors and depositing a second polycrystalline silicon for gate electrodes; patterning and etching the second polycrystalline silicon to form gate electrodes over parts of the single-crystal silicon resistors; implanting a dopant of the first conductivity type at more than 1×10 19 atoms/cm 3 into some regions of the first region of the single-crystal silicon resistors; implanting a dopant of the second conductivity type at more than 1×10 19 atoms/cm 3 into some regions of the second region of the single-crystal silicon resistors; forming an intermediate insulation film on the SOI substrate; forming contact holes in the intermediate insulation film on the SOI substrate; forming metal lead wires in the contact holes; and forming a protective film.