Patterned infrared spectral filter directly deposited onto cooled substrates

A method for depositing patterned infrared thin film spectral filters directly onto substrates at low temperatures (200 degrees C) is described. Energetic deposition methods (ion-assisted and laser-assisted) were used to avoid heating the substrates, while a multilayer photoresist lift-off technique was applied to pattern the structures. The process produced durable films capable of surviving harsh processing conditions. This is a promising method for depositing patterned coatings directly onto infrared focal plane detector arrays.