Silicon Nitride Coatings on Molybdenum by RF Reactive Ion Plating

Abstract

Rf reactive ion plating technique has been applied to the preparation of protective silicon nitride coating on molybdenum. All the deposits prepared at deposition temperature of less than 1O00~ were amorphous. Silicon in deposits was found to be present as nitride by Auger electron spectroscopic, infrared absorption spectroscopic, and x-ray diffraction analyses. Nearly stoichiometric silicon nitride deposits were obtained at a deposition rate of as high as 1 ~m/min. Several factors affecting the stoichiometry of the silicon nitride were discussed. Oxidation test of the coated specimens showed that the silicon nitride layer obtained under optimum conditions protected the molybdenum substrate from oxidation in Ar-l% O2 gas mixtures up to approximately 1200~ Typical pitting corrosion was observed in the coating film at the higher temperatures.

Preparation of AIN Coatings on Mo by RF‐Reactive Ion Plating: The Deposition Mechanism

“…The A1N coating improved the oxidation resistance up to about 1200~ which is similar to the result of SigN4 coatings (4). Pinholes present in the Si3N4 films ion plated on Mo cause the pitting corrosion of Mo under a high temperature oxidizing e n v i r o n m e n t (5).…”

“…The thermodynamic equation for the liquidus of a congruently melting, narrow homogeneity range compound has been derived in a number of papers (1)(2)(3)(4)(5)(6). That given by Vieland (6) has been widely used, extended to ternary systems, and used with an associated solution model for the liquid (7-10) following Jordan's development of a simplified version of this model (11,12).…”

“…The effect may be minimized by use of low-Z materials (1,2). In our laboratory, a series of studies of ceramic coatings such as SiC (3) and Si3N4 (4,5) on Mo have been carried out from the standpoint of low-Z coating and the oxidation-resistant coating. This report describes the preparation of the coatings of A1N on Mo by reactive ion plating.…”

Plasma-enhanced chemical vapour deposition of silicon nitride from SiCl4, nitrogen and hydrogen on hard metals

“…As laminated material it is used to a high degree in microelectronics [1]. Because of its relatively great hardness and its chemical and oxidation resistance, however, its use as a wear-resistant coating [2] and as anti-corrosive or thermostable layer [3] is also possible.…”