Platinum Protective Coatings Processed by Organometallic CVD

Abstract

CVD of noble metals creates great technological interest in various fields, such as electronic devices, protective coatings, or catalysts. In particular, the deposition of platinum by organometallic (OM)CVD is widely used in the microelectronics industry, for example, for the fabrication of electrodes for direct random access memories (DRAM).However, OMCVD of platinum as part of protective coatings is a rather unexplored field. In the latter case, the complex shape of pieces to protect requires a deposition process providing an integral and homogeneous layer. State-of-the-art alumina-forming coatings using platinum layers are processed by pack cementation.The performance of coatings processed in this way is very sensitive to impurities such as chlorine, sulfur, or phosphorus. Alternatively, the high purity and the conformal growth of the films, together with the low waste of the process, are major advantages of the OMCVD technique. We recently investigatedOMCVDPt films as part of a Pt-Al coating system, used for the protection of titanium alloys in the aeronautics industry through the formation of an external barrier layer of alumina. The overall process and the properties of these coatings are presented in the literature.