Patent ID: 6623606
Filing Date: 2003-09-23
Classification: C23C,H01J,H01L

Abstract:
In a sputter deposition method of coating semiconductor wafer substrates, in a sputter coating vacuum chamber, from a relatively thick sputtering target of a given design having a sputtering surface thereon that substantially erodes over its life, the improvement of maintaining sputtered film thickness uniformity across the surfaces of the substrates, from substrate to substrate, the method comprising the step ofprogressively reducing target-to-substrate spacing as a function of target erosion, which function has been empirically derived based on film thickness uniformity measurements to cause a film of a given uniformity to be sputtered onto a substrate from a target of the given design, so as to vary the distance from the substrate to the eroded sputtering surface so as to maintain film thickness uniformity across the surfaces of the substrates over the course of coating successive substrates.