Bell Telephone Laboratories

At&t Bell Laboratories

Martin E Poulsen

Frederick Vratny

George E Georgiou

Victor Andrew Firtion

Thomas Edward Saunders

Leif Rongved

Alfred Zacharias

Donald R Herriott

An improved X-ray source for a lithographic system comprises a double-angle conical target. The target is characterized by a small apparent source diameter and an efficient cooling system. Submicron resolution and high-power operation are thereby made feasible.

X-ray source comprising double-angle conical target

It has been discovered that the diffusion of hydrogen species into the outside or water-cooled surface of a pure palladium anode included in an X-ray source causes various deleterious effects. To avoid these effects, a limited-depth hydrogen-barrier layer made, for example, of Pd.sub.3 Sn is formed within the anode extending from the outside surface thereof. The inside or target surface and a major extent of the palladium anode remain virtually unaffected during the forming step. The desired palladium emission characteristic of the anode is thereby preserved. In practice, the modified anode remains free of hydrogen and, as a result, exhibits a particularly advantageous long-life property. Such an anode constitutes an important part of a high-power X-ray lithographic system adapted for making VLSI devices.

X-Ray source and method of making same

An apparatus and method for holding a thin workpiece such as a semiconductor wafer for operations which require the workpiece to have a high degree of planarity such as photolithographic printing includes positioning the workpiece onto a planar holding face comprising the points of a multiplicity of regularly spaced-apart substantially parallel pins with a thin rim encompassing all pins to contain a vacuum in the region adjacent to the workpiece. The small abutting area of each pinpoint abutment reduces the probability of dirt particles collecting on the holding face and provides a high thrust pressure to dislodge dirt particles interposed between the abutment and the workpiece. A small amount of lateral motion is imparted to the workpiece when it first contacts the holding face to brush off any dirt particles on the abutments.

Apparatus and method for holding and planarizing thin workpieces

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New Providence, NJ, United States of America

Martin E Poulsen