Crystalline Structure Changes of Molybdenum Silicide Films Deposited by Sputtering and by Coevaporation after Isochronal Annealing

Abstract

Crystalline structure changes of molybdenum silicide films after isochronal annealing are studied by x‐ray and transmission electron microscopy. Two types of films deposited by sputtering from a hot pressed source and coevaporation of molybdenum and silicon, with controlled stoichiometry of , are prepared. For both types of depositions, the films that are as‐deposited and annealed at temperatures below 350°C are amorphous, but those annealed between 400° and 600°C show hexagonal . Transformation from hexagonal to tetragonal occurs above 700°C for the coevaporated film, whereas it proceeds gradually above 800°C for the sputtered film. A carbon stabilized phase is observed above 750°C for the sputtered film, which suggests that the sputtered film is contaminated by carbon during the deposition. Formation of the Mo‐rich silicides and above 700°C is evidence that the deposited films become Mo‐rich during the annealing due to slight oxidation of the film surface.