International Business Machines Corporation

Ollie C Woodard

Edward V Weber

Alan V Hall

Hans C Pfeiffer

Michel S Michail

John L Mauer, Iv

Donald E Davis

Merlyn H Perkins

Maurice C Williams

An electron beam method and apparatus, for writing patterns, such as on semiconductor wafers, in which the writing field is divided into a large number of overlapping subfields with a predetermined periodicity. Subfield to subfield moves are made in a stepped sequential scan, such as raster, while patterns, within a subfield, are addressed using vector scan and written using a sequential scan. Significant improvement in throughput results by the use of this electron beam method and apparatus which preferably employs magnetic deflection for the sequential scanning the subfields and electric deflection for vector scanning within the subfield.

Electron beam system

A method and apparatus is described for performing automatic overlay measurements on wafers utilized in semiconductor manufacturing. The overlay measurements are made at selected sites on a given wafer where a single bar pattern has been overlaid over a double bar pattern. The position of the single bar center line with respect to the center line between the double bars is a direct indication of the overlay error of the two patterns. The overlay error is measured in both the X and Y dimensions and is utilized to monitor the overlay error or to produce statistics and correlations to system parameters so that the sources of overlay errors may be identified and the errors eliminated or minimized on subsequent wafers being processed.

Automatic overlay measurements using an electronic beam system as a

Electron current regulator for an electron discharge device

A beam of charged particles has its alignment and brightness alternately controlled in accordance with the current of the beam. The measurements of the current and any corrections for alignment or brightness are made when the beam is not applied to a target.

Method and apparatus for controlling brightness and alignment of a beam

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Poughkeepsie, NY, United States of America

Ollie C Woodard