Pre-ionization aided sputter gun

Abstract

In the present device the lower section is an external plasma gun which acts as a source of ionized gas. The upper section of the device is a magnetron which has a plasma chamber and which includes both a source of magnetic flux as well as the apparatus necessary to generate an electrostatic field so that within the plasma chamber of the magnetron there are EXB forces. The magnetron is supported in close proximity to, and is electrically insulated from, the external plasma gun. The above arrangement permits the magnetron to produce and maintain a plasma phenomenon with a very low pressure of gas (of the order of one millitorr to two tenths of a millitorr) in the vacuum chamber. Because of the reduced pressure in the vacuum chamber: the mean free path is longer than in the prior art and thus the throw distance to the substrate from the target can be much higher than in the prior art; there is reduced contamination in the vacuum chamber and in particular at the target and the substrate; there is better adhesion of the sputter particles to the substrate; and there is less gas and vapor occlusion inthe sputter film which in turn leads to a denser film.