APPARATUS FOR SPUTTER DEPOSITION

摘要

In accordance with one specific embodiment of the present invention, the apparatus (44) for sputter deposition within an evacuated volume (14) comprises a compact ion source (46) to generate ions (50, 52) into which an ionizable gas is introduced and from which ions leave with directed energies near to or below the sputtering threshold, a sputter target (54) near that source and located within the beam of ions leaving that source, a grounded shield (58) surrounding the sputter target and defining that portion of the target which is to be exposed to sputtering, and a power supply to bias the target so that ions are attracted to and sputter the target. Particles sputtered from the target are deposited on a deposition substrate (64) separate from both the ion source and the sputter target. In the case of an insulating target, the target is biased with a radiofrequency power supply and the bias has a mean negative value rather than a direct-current negative value. The rate and energy with which the ions arrive at the target together determine the rate with which that target is sputtered and the rate with which the thin film is deposited on the substrate. In using a compact gridless ion source, the high pressure required for generating ions is confined to the ion source and the gas load for pumping is reduced. For ion energies at or near the sputtering threshold, the sputtering from extraneous hardware is reduced or eliminated. In addition, the target biases can be low enough to minimize the damage due to energetic neutrals that result from the reflection of energetic ions striking the target.