VERFAHREN ZUM HERSTELLEN VON OPTIMIERTEN KOMPLEMENTAEREN MOS-FELDEFFEKTTRANSISTOREN IN VLSI-TECHNIK.

摘要

Masking for the individual ion implantations is carried out with photoresists and/or Si oxide or Si nitride structures and the gate electrodes are provided with spacer oxide to prevent under-diffusion of the implanted source/drain zones under the gate area. The novel features are (a) deposition of SiO2 film in a thickness corresp. to the spacer oxide width of the gate of the future p-channel transistors on a p- or n-doped Si substrate, (b) deposition of a Si nitride film; (c) carrying out a photoresist technique and structurisation of the double SiO2-Si nitride film (d) carrying out thermal oxidn. after removal of the photoresist (e) carrying out final implantation for the n-channel transistor; (f) deposition a second SiO2 film and anisotropic re-etching (g) carrying out source/drain implantation to produce the n-channel transistors and diffusion of the implanted dopants; (h) applying a photoresist mask to the n-channel zones not covered by the double film and removing the residual second SiO2 film on the stages in the p-channel zone by isotropic over-etching; (i) removing the Si nitride film; (j) anisotropic re-etci--re-etching of the SiO2 film ; (k) carrying out source drain ion implantation to produce the p-channel transistors and removal of the photoresist mask; and (l) prodn. of the intermediate insulating oxide, the contact hole zones and the metallisation in conventional manner.