Method and apparatus for film thickness adjustment

摘要

An ion source is used to adjust film thickness uniformity. Voltage is adjusted based on the film thickness to remove material on thicker parts of the substrate while removing almost no material on the thinner part of the substrate. Special procedure is used to obtain virtually uniform film without reducing minimum thickness on a substrate. Source calibration is used to maintain precise etch rate control. Film thicknesses can be adjusted to less than 0.5 nanometers uniformity.