Abstract: A lithography tool having an improved focus system. The focus system comprises a lens mounted in a nosepiece which defines a chamber. The chamber defines an onifice through which the lens system may see a workpiece. An air supply is provided to supply a regulated and measured air flow to the chamber. By measuring the air flow into the chamber, the rate of air flow through the orifice may be determined. The rate of air flow through the orifice is proportional to the gap between the orifice and a workpiece.

Abstract: A steering mirror for use with a laser pattern generator. A reflective surface is mounted on a pivotally mounted extended member. A piezo electric crystal abuts the extended member and voltage applied to the crystal causes deformation of the crystal and ultimately movement of the reflective surface. A differential impedence transducer is coupled to the extended member to detect movement of the steering mirror. In this manner, the position of the mirror can be accurately controlled.

Abstract: The present invention provides a part holder for use in a pattern generation apparatus having a reference point which has a constant spatial relationship between itself and a work piece mounted on the part holder. The part holder is comprised of a material having a low coefficient of thermal linear expansion. In one embodiment, the part holder is formed in sections combined with bonding using a suitable adhesive, such as a low out-gassing epoxy. However, single piece construction may be utilized. In order to eliminate variations in the spatial relationship between the part holder and a coordinate system fixed in space resulting from differences in expansion rates between the part holder and the substrate on which it is mounted, kinematic mounting is employed. The resulting part holder maintains a constant distance between the reference point and the work piece.