METHOD FOR MANUFACTURING VLSI COMPLEMENTARY MOS-FIELD EFFECT TRANSISTOR CIRCUITS

摘要

A method for manufacturing a CMOS circuit wherein a process sequence matched to an n-tub manufacture is carried out. Short-channel properties of n-channel transistors are improved by performing double boron implantations of the channel regions. A shared channel implantation is executed for both transistor types. Compared to traditional CMOS processes in n-tub structure, this eliminates involved masking steps. Also, the polysilicon gate is shielded from the boron ion implantation by means of a masking re-oxidation step and the under-diffusion given n-channel an p-channel transistors is greatly reduced by means of pull-back of the boron source/drain implantation. This contributes significantly to a symmetrical UT behavior of the transistors and to the attainment of high switching speeds. The method is used in the manufacture of VLSI CMOS circuits in VLSI technology.