a superconducting material made of tungsten or molybdenum containing a specified amount of silicon , a wiring made of this superconducting material , and a semiconductor device using this wiring . the above - mentioned superconducting material undegoes no damage even in the steps of heat treatments effected after the formation of a wiring therefrom by virtue of its high melting point , and can be very easily patterned by reactive ion etching using sf 6 as an etching gas , which has heretofore been generally employed . these features , in which conventional superconducting materials are lacking , allow the superconducting material of the present invention to exhibit excellent properties particularly when used in the wirings of a semiconductor device .