| 摘要 |
<p>A positioning stage (8) which achieves high-speed step-and-repeat alignment of a semiconductor wafer (2) to a mask with a full six degrees of freedom. A precision planar translational stage is mounted on a rotating stage (20) to allow a single-laser interferometric system to be utilized to make precise measurements of translational (X and Y) and rotational (Υ) positions. The entire X-Y-Υ stage system can also be moved vertically in a Z direction, or tilted with respect to the X-Y plane, by independently adjustable flexible mounts (26a, 26b, 26c). The center of rotation of the rotational stage (20) is on the beam axis (6), so that registration of the wafer (2) to a mask is simplified. Because the mass of the rotating stage (20) is not moved during high-speed X and Y-positioning steps, fast response is possible. In lithography applications, one rotational correction at the beginning of the writing procedure suffices for all the chips on the wafer, if all the rows and columns of chips are perfectly straight. Besides its usefulness in litography with a flood ion beam, the invention is also useful in direct-write electron- or ion-beam lithography systems with focused beams, to obviate the need for high-speed electronic scan rotation.</p> |
