Method of depositing nanotwinned nickel-molybdenum-tungsten alloys

Abstract

The present invention is directed to the synthesis of metallic nickel-molybdenum-tungsten films and coatings with direct current sputter deposition, which results in fully-dense crystallographically textured films that are filled with nano-scale faults and twins. The as-deposited films exhibit linear-elastic mechanical behavior and tensile strengths above 2.5 GPa, which is unprecedented for materials that are compatible with wafer-level device fabrication processes. The ultra-high strength is attributed to a combination of solid solution strengthening and the presence of the dense nano-scale faults and twins. These films also possess excellent thermal and mechanical stability, high density, low CTE, and electrical properties that are attractive for next generation metal MEMS applications. Deposited as coatings these films provide protection against friction and wear. The as-deposited films can also be heat treated to modify the internal microstructure and attendant mechanical properties in a way that provides a desired balance of strength and toughness.

Dependencies are inferred from the claim text.