Apparatus for, and method of, depositing a film on a substrate

Abstract

An electrical field between a positive anode and a negative target in a cavity and a magnetic field in the cavity cause electrons from the target to ionize neutral gas (e.g. argon) atoms in the cavity. The ions cause the target to release sputtered atoms (e.g. aluminum) for deposition on a substrate. A shield between the target and the substrate inhibits charged particle movement to the substrate. The anode potential may be positive, and the shield and the magnetic members may be negative relative to the anode, to obtain electron movement to the anode, thereby inhibiting the heating of the shield and the magnetic members by electron impingement. The anode may be water cooled. The magnitude of the positive anode voltage relative to the target voltage provides selectively for (a) a uniform thickness of sputtered atoms on the walls of a groove in the substrate or (b) a filling of the groove by the sputtered atoms and a uniform thickness of deposition on the substrate surface including the filled groove. Progressive increases in the anode voltage produce progressive increases in the rate of the sputtered atom deposition on the substrate. A sensor may receive infra red energy passing from the substrate through a hole in the anode to provide signals having characteristics indicating variations in the substrate temperature. The anode voltage is varied in accordance with the characteristics of such signal to regulate the temperature of the substrate. The target voltage is preferably varied with the anode voltage variations to maintain the anode-cathode voltage difference substantially a constant.