Tin is added to a zinc cathode target to enhance the sputter efficiency of the
target. Films deposited using the cathode, e.g., greater than zero but less than
10 weight percent tin and greater than 90 but less than 100 weight percent zinc
improve the chemical durability of a high transmittance, low emissivity coating
stack over coating stacks having zinc oxides without tin oxide. High transmittance,
low emissivity coating stacks are heated with the heated coating having reduced
haze by selecting the thickness of metal primer layer between an infrared reflective
film, e.g. a silver film and a dielectric film, e.g., a 52-48 zinc stannate, zinc
oxide, tin oxide film or a zinc oxide film. Also disclosed are enhancing films
that lower the resistivity of silver films deposited thereon and improve chemical
durability of the coating stack.
