| 摘要 |
PURPOSE:To extremely shorten the delay time of signal transmission in the wirings by forming a double-layer wiring structure through vacuum deposition of super-conductive metal on metal silicide layer or normal metal layer and by operating a circuit at the liquid helium temperature. CONSTITUTION:A field oxide film 12, a gate oxide film 13, a polysilicon layer 14, N<+> diffusion layers 15, 16 and a PSG film 17 are formed on the P type Si substrate 11 and moreover a molybdenum silicide layer 18 and a Nb layer 19 are also formed thereon. A layered structure of the molybdenum silicide layer 18 and Nb layer 19 is used as the wiring and is operated at a liquid helium temperature (4.2K). At an ultralow temperature ambient, the Nb wiring becomes a superconductive wiring. Thereby, a signal delay time can be shortened remarkably and reaction between superconductive metal and Si can be prevented effectively because the molybdenum silicide layer is provided and moreover close contactness of wirings and distortion of stress can be improved remarkably. Such effect can also be realized by using Pb, NbN, MoN and an alloy including these as the superconductive metal. |
