Stage apparatus for semiconductor inspection and lithography systems

摘要

A semiconductor sample is received on a chuck of a stage that is movable with respect to a stage frame. The stage, chuck, and sample are moved under an inspection or exposure head for inspecting or exposing the sample, and multiple 2D encoder heads are coupled with the chuck. Multiple 2D encoder scales are coupled with a base through which the head is inserted, and a stage encoder is positioned on the stage frame. Movement of the stage, chuck, and sample is controlled based on a position detected by at least one of the 2D encoder heads until a predefined position that is within a gap that is not covered by the 2D encoder scales is reached. Movement control of the stage, chuck, and sample is switched to being based on a position detected by the stage encoder when such predefined position that is within the gap is reached.

主权项

1. An apparatus for fabricating, measuring, or inspecting a semiconductor wafer, the apparatus comprising:
a head for directing an electromagnetic beam towards a sample in the form of a semiconductor wafer or photolithography mask; a base having a hole through which the head is inserted; a movable stage having a chuck for holding the sample; a stage controller for controlling movement of the chuck and sample with respect to the head; a plurality of two dimensional (2D) encoder scales that are affixed to a surface of the base that is opposite a surface of the chuck and are statically placed with respect to the head, wherein the 2D encoder scales are arranged to form a gap around the hole of the base through which the head is inserted; a plurality of chuck encoder heads affixed to the chuck for detecting a position of the stage and sample relative to the head by sensing of the 2D encoder scales; and a stage encoder for detecting a position of the chuck and sample, wherein the stage controller is configured to control movement of the movable stage and chuck based on either (i) the position detected from the chuck encoder heads when such chuck encoder heads are not transitioning across the gap between the 2D encoder scales or (ii) the position detected from the stage encoder when the chuck encoder heads are transitioning across such gap.