International Business Machines Corporation

Robert A Simpson

Edward V Weber

Hans C Pfeiffer

Werner Stickel

Jan Rogoyski

Ralph R Trotter

John R Rudert, Jr

Wallace J Guillaume

John F Loughran

A data compaction technique permits electron beam lithography systems to operate more efficiently in the fabrication of complex computer chips. One or more building block patterns are selected for the design to be encoded. Each shape in the set of building block patterns is given a sequence number for use in a data word for the design. The set of shape descriptors for each block is stored in a reference memory. The data word referencing a block includes a number of bytes which specify the stored block pattern data and control bits corresponding to sequence numbers of the pattern shapes in a maximum shape configuration. Each shape is assigned a bit according to its sequence number.

Data compaction techniques for generation of a complex image

An E-beam alignment correction system employing an up-up integration technique. Input signals during each scan period are integrated and digitized then held in respective registers. The value in one register is converted to its negative value then digitally combined with the other value to generate an alignment correction value. This technique eliminates the requirement of positive and negative integrations needed with up-down integration techniques and droop of the sample and hold device as a function of time. A common analog path is used so that errors add out during digital combination of signal values.

Alignment correction technique

A method of forming inspection patterns for inspecting a workpiece, e.g., for electron beam inspection of optical photomasks. The inspection patterns are formed from the workpiece patterns themselves by applying a first positive windage to the workpiece patterns, inverting the first positive windaged workpiece patterns and applying a second positive windage to the inverted first positive windaged workpiece patterns. The inspection patterns so produced will contain the requisite guard band and the requisite overlap of abutting patterns.

Method for generating inspection patterns

An alignment system for registration of a scanning beam in a mask inspection tool. Minimum scan widths (W) in the registration process are attained thereby increasing registration sensitivity. This technique allows initial placement of the E-Beam to be outside the capture range so that the scan on one side is completely off the metal (on glass) and the scan on the other side is completely on the metal. Correction signals are obtained by comparing the backscattered electron signals from the two scans with the magnitude of the signal being indicative of the amount of correction required and the sign being indicative of the direction of correction.

Alignment technique

An electron beam system for non contact testing of three dimensional networks of conductors embedded in dielectric material, specifically detection of open and short circuit conditions. Top to bottom and top to top surface wiring is tested electrically without making physical electrical contact. The system comprises two flood beams and a focus probe beam wih one flood beam located at either side of the specimen. Proper choice of acceleration potentials, beam currents and dwell times of the beams allow alteration of the secondary electron emission from the specimen in such a way that electrical properties of the conductor networks can be measured directly. The difference in secondary electron emission resulting from different surface potentials is detected as a strong signal which allows clear discrimination between uninterrupted and interrupted as well as shorted pairs of conductors. This testing system can be applied to the high speed testing of advanced VLSI packaging substrates as well as to the greensheets, sublaminates, and laminates from which they are fabricated.

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Wappingers Falls, NY, United States of America

Robert A Simpson