| 摘要 |
PURPOSE:To remove a parasitic MOSFET positively by taperingly forming a contact window for shaping an electrode to an insulating layer molded onto the active region of a semiconductor substrate when the contact window is formed to the insulating layer and shaping a high impurity concentration region with a reverse conduction type contacting with the active region through ion implantation by utilizing the difference of the thickness of the insulating layer. CONSTITUTION:A P type Si substrate 1 is coated with an SiO2 film 5 and openings are bored while being made correspond to N<+> type diffusion regions to be formed, and the N<+> type regions 2, 3, 16, 17 as the active regions of a source and a drain, etc. are diffused and shaped. The oxide films 5 with approximately 8,000Angstrom thickness are formed onto these regions by oxidizing the whole surface of the substrate 1, contact sections among the diffusion layers and metallic wiring are removed selectively through the irradiation of plasma, and oxide films 18 with approximately 25 deg. tapered angles are shaped near the openings. Sections in which there is no danger of which the parasitic MOS transistor is formed are masked by resists 19, and P type guard rings 14 are shaped around the regions 2, 3, in which there is the danger mentioned above, through ion implantation. |
