Measuring and testing – Testing of apparatus
Reexamination Certificate
1997-10-10
2001-03-27
Raevis, Robert (Department: 2856)
Measuring and testing
Testing of apparatus
Reexamination Certificate
active
06205870
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to automated substrate processing systems and methods.
An automated substrate processing system typically includes a vacuum chamber with a support mechanism for supporting a substrate during processing, and an automated transfer mechanism, such as a robotic device. In operation, the transfer mechanism loads and unloads substrates into and out of the vacuum chamber. Over time, substrates may become misaligned with respect to the processing system. Significant substrate misalignment may reduce the number of devices that can be formed on a particular substrate or may cause the substrate to break inside the vacuum chamber. When a substrate breaks inside a vacuum chamber, the chamber must be opened and exposed to atmospheric pressure, the chamber must be cleaned, and the chamber must be pumped back down to a sub-atmospheric pressure suitable for processing. Such a procedure may take up to twenty-four hours to complete, significantly delaying the time during which the system can be used to process substrates.
SUMMARY OF THE INVENTION
In one aspect, the invention features a system for processing substrates, comprising: a vacuum chamber; a substrate support located inside the vacuum chamber and constructed and arranged to support a substrate during processing; and a substrate alignment detector constructed and arranged to detect if the substrate is misaligned as the substrate is transferred into the vacuum chamber based upon a change in a physical condition inside the system.
Embodiments may include one or more of the following features.
The substrate alignment detector may comprise a vibration detector coupled to the substrate support. The vibration detector may comprise an accelerometer or an optical sensor for detecting the position of the substrate. The alignment detector may be constructed to produce a signal indicative of the degree of substrate misalignment. A monitor may be coupled to the alignment detector and configured to trigger an alarm when the signal produced by the alignment detector exceeds a threshold value. A controller may be provided for determining if the substrate is misaligned and for recalibrating the system.
A substrate aligner having one or more alignment pins for aligning the substrate with respect to the substrate support may be provided. The substrate aligner may be movable toward and away from a substrate that is positioned inside the vacuum chamber, and the one or more alignment pins are positioned to contact a substrate that is misaligned with respect to the substrate support and to guide the misaligned substrate into alignment. The substrate aligner may comprise one or more lift pins for supporting a substrate above the substrate support. A vibration detector may be provided for determining if a substrate contacts one or more of the alignment pins of the substrate aligner. The substrate alignment detector may be configured to determine which of the one or more alignment pins contacts the substrate. The substrate alignment detector may comprise three vibration detectors positioned at non-collinear locations with respect to the substrate aligner.
In another aspect, the invention features a method for processing substrates, comprising: transferring a substrate into a vacuum chamber that has a substrate support for supporting a substrate during processing; and detecting if the substrate is misaligned with respect to the substrate support by detecting vibrations inside the vacuum chamber.
Embodiments may include one or more of the following features. The substrate may be processed and unloaded from the vacuum chamber. The substrate may be determined to be misaligned with respect to the substrate support when the amplitude of the detected vibrations exceeds a threshold value. The system may be recalibrated after the substrate is determined to be misaligned with respect to the substrate support. The system may be recalibrated by: recording the position of the unprocessed substrate as it is being transferred into the vacuum chamber; recording the position of the processed substrate as it is being unloaded from the vacuum chamber; and compensating for any substrate misalignment based upon the difference in the recorded substrate positions. The system may be recalibrated by determining the magnitude (R) and direction (&phgr;) of substrate misalignment, and compensating for any substrate misalignment as the substrate is being transferred into the vacuum chamber based upon R and &phgr;.
In another aspect, the invention features a method for processing substrates, comprising: transferring a substrate into a vacuum chamber that has a substrate support for supporting a substrate during processing; recording the position of the substrate as it is being transferred into the vacuum chamber; detecting if the substrate is misaligned with respect to the substrate support; processing the substrate; unloading the processed substrate from the vacuum chamber; recording the position of the processed substrate as it is being unloaded from the vacuum chamber; and compensating for any substrate misalignment based upon the difference in the recorded substrate positions.
Among the advantages of the invention are the following. The invention can significantly reduce the substrate breakage rate by detecting when a substrate is likely to be misaligned. This increases the time during which substrates can be processed, and increases the throughput rate and the processing yield. Furthermore, the invention can significantly improve the quality of the substrate process by reducing the number of times the system must be opened and exposed to atmospheric conditions.
Other features and advantages of the invention will become apparent from the following description, including the drawings and claims.
REFERENCES:
patent: 4727593 (1988-02-01), Goldstein
patent: 4873447 (1989-10-01), Imahashi
patent: 5352294 (1994-10-01), White et al.
patent: 5466945 (1995-11-01), Brickell et al.
patent: 5518593 (1996-05-01), Hosokawa et al.
patent: 5535306 (1996-07-01), Stevens
patent: 5537311 (1996-07-01), Stevens
patent: 5563798 (1996-10-01), Berken et al.
patent: 5567476 (1996-10-01), Law et al.
patent: 5607602 (1997-03-01), Su et al.
patent: 5611865 (1997-03-01), White et al.
patent: 5690744 (1997-11-01), Landau
Demaray Richard Ernest
Halsey Harlan L.
Hosokawa Akihiro
Inagawa Makoto
Mullapudi Ravi
Applied Komatsu Technology Inc.
Konrad Raynes & Victor LLP
Raevis Robert
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