Publication Details (including relevant citation information):
J. Vac. Sci. Technol. A 6(5), 2883 - 2886 (1988).
This article was presented at the 34th National Symposium of the AVS, Anaheim, U.S.A., 1987.
|07.30.Kf||Vacuum chambers, auxiliary apparatus, and materials|
|85.40.Hp||Lithography, masks and pattern transfer|
Recently an ultrahigh vacuum environment has been necessary to reduce impurities in the production of high‐density integrated circuits. In particular, tables permitting precise positioning with low outgassing rates have been required for thin‐film processing equipment and surface analysis systems using spot beams. An X–Y–θ three‐axis table made of aluminum alloys with a special surface treatment for ultrahigh vacuum environments has been developed. The stroke of the X and Y axes is 75 mm, and the rotational range of the θ axis is 360°. The X and Y axes are driven by built‐in stepping motors, connected directly to aluminum alloy ballscrews. The stator of the motor is made using stainless‐steel sheath cable. The screws and nuts of the ballscrews are coated with TiC, and the balls are coated with Ag. The characteristics of the table have been investigated in atmosphere before and after baking. The measured error motions for the X axis were pitch ±2.3 μm/75 mm and yaw±1.4 μm/75 mm; and for the Y axis were pitch ±0.78 μm/75 mm and yaw ±0.22 μm/75 mm. The resolution and repeatability for the X and Y axes was 15 μm ±2 μm/pulse, and for the θ axis was 1.8° ±0.09°/pulse. The mechanical characteristics were maintained after baking. The table moved in an ultrahigh vacuum environment of the order of 10−11 Torr as it had in atmosphere.