The Perkin-elmer Corporation

Applied Materials, Inc.

Allen M Carroll

Lee H Veneklasen

Richard L Lozes

Daniel L Cavan

Andrew Julius Muray

Glen E Howard

William A Eckes

Charles S Biechler

Donald J McCarthy

Steven A Lyons

Richard E Graves

Dose conservation is used during pattern modification in the data preparation phase of scanning beam lithography. The features to be exposed on a substrate, such as a mask or direct written semiconductor wafer, are corrected while neighboring features suffer little or no change. Thus, the edge of a feature is moved in terms of its exposure location without appreciably affecting the scattering into its neighbors. This achieves a developed feature which meets the intended design edge location. This process also corrects for variations in resist profile angles which otherwise may vary depending upon localized feature packing density. Not only is the feature edge moved but its dose per area is adjusted while conserving total dose over the feature.

Border modification for proximity effect correction in lithography

A specimen distance measuring system uses a plate (36) to obstruct the flux of backscattered electrons produced by an electron beam (18), and to cast a shadow across a measurement detector (32) which is sensitive to the position of the shadow. The shadow plate (36) and measurement detector (32) are aligned at an angle of approximately 45 degrees with a substrate (14) in order to allow calibration of the distance measuring system by scanning the electron beam (18). The measuring system is particularly useful as a height sensor (10) in an electron beam lithography apparatus (12) for sensing the height of a substrate (14). The distance measuring system may also include a reference detector (34) which is positioned in order to receive backscattered electron flux without obstruction from the shadow plate (36). The use of such a reference detector (32) is advantageous in allowing compensation of the signals obtained by the measurement detector, in order to allow the height sensor to operate independently of variations in electron beam current, and variations in substrate backscatter coefficient. The reference and measurement detectors (34,32) may be aligned in a vertical or horizontal plane to be either parallel to or perpendicular to the bombardment electron beam (18). Active feedback may be provided from the height sensor (10) to a vertical stage actuator for adjusting the height of the substrate (14).

Specimen distance measuring system

A technique performed in a fixed address particle beam lithographic system where the writing is performed in the normal manner for writing a pattern, for example, a stripe on a resist having a selected feature width except that an additional row of alternate pixels is written either before or after the selected feature is written. The alternate pixels, when the resist is developed, will provide a feature width of approximately 1/2 a pixel wider than the selected feature width due to blurring of the latent image caused by scattering of the particle beam within the resist. Thus, the resolution of selectable feature widths is enhanced with little or no loss of throughput. The same technique can also be utilized to lengthen a feature by 1/2 a pixel width. The technique is disclosed primarily in a raster scan machine but also disclosed is the technique in a vector scan machine. Also disclosed is a flow chart showing the invention used while preparing the data to be written by the machine.

Virtual addressing for E-beam lithography

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Oakland, CA, United States of America

Allen M Carroll