International Business Machines Corporation

Rainer Butsch

John George Hartley

Werner Stickel

William A Enichen

Timothy R Groves

Michael Stuart Gordon

Across chip line width variations and other repetitive deviations from the design pattern desired in E-Beam lithography are compensated for by examining each of the regions (i.e., frames, stripes, etc.) of a patterned substrate, determining the amount of deviation for each region, and using the determined regional deviation as a local bias when patterning subsequent substrates. Thus, the E-Beam lithography tool will utilize both global and local biases in order to produce new patterned substrates which lack the deviations found when local bias was not applied. In this way, the root cause of the deviation does not need to be determined. The local bias can be applied directly by modifying the E-Beam lithography system tool commands to provide for patterning wider or thinner lines or to provide for greater or lesser exposure time. Alternatively, the local bias can be applied by varying the emission current of the electron gun for different regions of the substrate.

Emulation methodology for critical dimension control in E-Beam

A method for monitoring resist charging in an electron beam lithography system is disclosed. The method involves the use of a reference plate (REFP) registration scheme in which a resist-coated REFP having registration marks on a substrate is prepared and scanned. The scanning process includes the deposition of an amount of charge on the surface. Then the REFP is coated with a resist to be tested and scanned again. The difference between the two scans is calculated. Preferably, each scan is performed first with the stage moving in a forward-ordered serpentine path in the tool to determine the perceived positions of the registration marks and then in a backward-ordered serpentine path. As the tool's stage moves from field to field, a small charge is deposited on the REFP to simulate the effect of a writing process. The difference between the forward and reverse scan position measurements is then determined. As any intrinsic positional errors in measurement will cancel out, the forward/backward error provides a monitor of the magnitude of resist charging.

Method for monitoring resist charging in a charged particle system

A method is disclosed for improving the electron beam apparatus lithography process wherein the calibration procedure for the apparatus is improved by using the product pattern and stepping sequence used to make the mask on a calibration plate and/or calibration grid and to determine improved apparatus correction errors which errors are used to control the apparatus for making an improved mask. The well-known EMULATION procedure is improved by calculating additional field correction errors based on a two step registration procedure to determine X/Y apparatus stepping errors. The LEARN procedure based on a static calibration grid procedure is improved by employing the duty cycle of the product pattern to calibrate the apparatus to determine deflection beam errors.

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Fairport, NY, United States of America

Rainer Butsch