Patent ID: 7402228

Claim:
An apparatus for forming thin film on each of a plurality of substrate to make photo-mask blanks, comprising: a sputtering chamber for carrying out sputtering to form the thin film on a surface of each substrate in a sputtering time, comprising therein: a single sputtering target, a target holder, and a substrate holder capable of holding a substrate in a horizontal state, having a rotation mechanism and being rotatable around its center axis, wherein the number of rotations of the substrate is controlled to be an integer during the film formation, said substrate holder and said target holder being placed so that the target is held opposite to the substrate and a center axis of the target deviates from a center axis of the substrate; a first load lock mechanism for introducing the substrate into the sputtering chamber and a second load lock mechanism for discharging the substrate with a film formed thereon in the sputtering chamber, each of said first load lock mechanism and the second load lock mechanism comprising a load lock chamber, and a conveyer for conveying each of the plurality of substrates one by one for introducing each of the substrates into the sputtering chamber, wherein said conveyer is capable of conveying one substrate at a time to introduce the substrate in the sputtering chamber so that the sputtering time for carrying out the sputtering for a substrate and an interval time which runs from an end of sputtering for one substrate to a start of sputtering for a next substrate are respectively made constant, and wherein the load lock chamber is capable of accepting one substrate at one time, so that introducing each substrate into and discharging each substrate from the sputtering chamber can be continuously made at a constant interval.