High rate deposition of MoSi2 films by selective co-sputtering

A new sputtering method has been developed to achieve the high rate deposition of refractory metal silicide films. This method employs a planar magnetron sputtering cathode with two coaxially wound electromagnet coils in a magnetic yoke and a target plate of multiring structure composed of silicon and molybdenum target pieces. The diameter of the glow ring can be changed by controlling the magnetomotive forces in the two electromagnet coils. The target consisted of a centre silicon disc and molybdenum and silicon target rings which concentrically surround the centre silicon disc. The glow ring diameter was controlled so that each of the target pieces was selectively sputtered. The amount of sputtered silicon and molybdenum was adjusted to obtain a film of the required thickness and composition on the substrate. Distributions of the composition and the film thickness of 37±0.5 wt.% Si and ±2% respectively were obtained over a 4 in wafer. The film was annealed at 1000°C for 30 min. A sheet resistance of about 2.3 Ω/□ was obtained for a film 300 nm thick with an average deposition rate of 95 nm min -1 .