Chartered Semiconductor Manufacturing Ltd (corporation)

Zadig Cheung-Ching Lam

Juan Boon Tan

Soon Ee Neoh

Kay Chai Ang

Ron-Fu Chu

A multi-segment alignment mark useful for a variety of processes is described. The multi-segment alignment mark comprises a plurality of segments wherein each of the segments comprises a series of sub-segments wherein each of the sub-segments comprises a series of spaces and lines, each sub-segment having the same width but having a different number of spaces and lines within the width depending on the relative width of the spaces and lines. A wafer stepper detects signals from each of the sub-segments and uses the best signal to achieve alignment.

Multi-segment global alignment mark

Wafer stepper method utilizing a multi-segment global alignment mark

This computer system, as well as its method of operation, corrects the position data used to define the location of alignment marks on a workpiece. The first step is to scan marks along a first direction to determine the direction of wafer scaling along the first direction. Second, scan marks along a second direction to determine the direction of wafer scaling along the second direction. Next, scan a first set of alignment marks on a workpiece oriented in a first direction and a second set of alignment marks on the workpiece oriented in a second direction in an initial sequence to collect initial direction data on the location. Then, scan the first set of alignment marks and the second set of alignment marks in a reverse sequence to collect reverse direction data on the location. Finally, average the initial direction data and the reverse direction data. This enables correction of false alignment data attributable to falsely measured locations of alignment marks.

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Arcadia, CA, United States of America

Zadig Cheung-Ching Lam