Deterministic control of thin film thickness in physical vapor deposition systems using a multi-aperture mask

A technique for controlling the thickness profile of a thin film in physical vapor deposition systems is reported. The technique uses a novel mask design with apertures of varying dimension to selectively deposit the required film thickness at predetermined locations across the aperture of the substrate. The technique has been used to correct the thickness uniformity of a 55 mm diameter, 280 microm thick, lithium niobate wafer to less than 0.5 nm rms, and also to improve the uniformity of deposited films in an Ion Beam Sputtering system to better than 0.5% over a 50 mm aperture.