Structural and optical properties of titanium aluminum nitride films (Ti1-xAlxN)

Titanium aluminum nitride films (Ti1-xAllambdaN) have been deposited by rea ctive magnetron cosputtering. Elemental compositions of these films have be en determined by core level photoelectron spectroscopy. Scanning electron m icroscopy reveals a columnar film growth. This is also reflected by the top ography of film surfaces as studied by atomic force microscopy. By x-ray di ffraction a crystalline atomic structure is revealed. Single phase samples can be obtained, consisting of the substitutional solid solution (Ti, Al)N. Crystallites show preferential orientation. The optical properties of thes e films have been investigated by spectrophotometry in the UV-VIS-NIR wavel ength range. Depending on the elemental composition, the optical constants vary from metallic to dielectric behavior. For film compositions with x <0. 5 typical features are a tunable transmission maximum and reflection minimu m in the visible spectral range, a high infrared reflection, and a low infr ared absorption. Due to these optical properties, Ti1-xAllambdaN films are promising candidates for applications such as coatings for solar control wi ndows and optical selective solar absorbers. (C) 2001 American Vacuum Socie ty.