摘要 |
<p>SEMICONDUCTOR WAFER PROCESSING A chuck for holding a workpiece (e.g., a semiconductor wafer) in a vacuum comprises a curved reference surface. By clamping the edges of the workpiece and maintaining its backside against the curved surface (or against pins mounted on the surface), the frontside of the workpiece can be thereby established in a precise equidistant relationship with respect to the reference surface. Such a chuck is advantageous for holding wafers to be lithographically patterned in a high-resolution way by electron-beam, ion-beam and X-ray-beam techniques.</p> |