Titanium Nitride and Zirconium Nitride As Non-Diffusing and Mechanically Hard Infrared Reflective Thin Film Coatings
Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
Gold has the highest infrared reflectance of any element and hence is widely used as a reflector of radiant heat. The nature of its high infrared reflectance arises from its characteristic electronic band structure. However, three problems are common when using gold coatings: 1. The diffusion of gold at elevated temperatures into other materials such as copper and silicon. In the case of copper, the reflective finish may entirely disappear, requiring recoating. In the case of silicon, diffusion may alter the semiconducting structure of an electronic device. Standard diffusion barrier metallizations of, for instance, TiPdAu still interdiffuse at short exposures at 600ŒC or long exposures at 100ŒC. 2. The mechanical softness of gold means that the coating is easily damaged.