SPUTTER DEPOSITION METHOD, SPUTTERING SYSTEM, MANUFACTURE OF PHOTOMASK BLANK, AND PHOTOMASK BLANK

摘要

A first target and a second target in the same vacuum bath is parallel to or inclined to sputter surfaces at both sides or an object to be sputtered. Power is simultaneously applied to the first and the second target. In the interaction of the first and the second target, because a sputtered particle emitted from one target reaches the sputter surface of the other target, the velocity of attaching the sputter particle onto the sputter surface is lower than that of removing the sputter particle by the sputter of the other target. Thereby, a layer is formed on the object by sputtering. According to the present invention, in forming a layer by a co-sputter using at least two kinds of targets which easily changes the composition of the layer, the mutual contamination or reform on the sputter surface of the target can be prevented. A layer can be formed by stabilizing discharge in sputtering. A high quality photomask blank with reduced defects can be stably manufactured.