Method and system using exposure control to inspect a surface
AssigneeKLA-Tencor Technologies Corporation
InventorsJenn-Kuen Leong, Guoheng Zhao, Mehdi Vaez-Iravani
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Abstract
A method and system of using exposure control to inspect a surface, such as a wafer. One inspection system comprises charge coupled devices (CCDs) as detectors. The exposure control function of each CCD is used to adjust integration times on individual taps of the CCD such that light scattered from the surface, which may contain multiple scattering regions, is within a dynamic range of the CCD during inspection.
Claims53
A system configured to inspect a wafer, the wafer comprising at least two regions that scatter light differently, the system comprising:
- a collector configured to collect light scattered from the wafer, the collector comprising a charge coupled device (CCD), the CCD comprising:
- a plurality of taps, each tap comprising a set of pixels, the CCD being configured to independently adjust an integration time of each tap depending on where the set of pixels of the tap is positioned to collect light scattered from the wafer, wherein the integration times of at least two taps positioned to collect light scattered from the at least two regions are different.
A system configured to inspect a wafer, the wafer comprising at least two regions that scatter light differently, the system comprising:
- a colletor configured to collect light scattered from the wafer, the collector comprising a charge couple device (CCD), the CCD comprising:
- a plurality of taps, each tap comprising a set of pixels, the CCD being configured to independently adjust an integration time of each tap depending on where the set of pixels of the tap is positioned to collect light scattered from the wafer, wherein the wafer comprises a first region that scatters light substantially randomly, and a second region that scatters light substantially periodically.
A system configured to inspect a wafer, the wafer comprising at least two regions that scatter light differently, the system comprising:
- a collector configured to collect light scattered from the wafer, the collector comprising a charge coupled device (CCD), the CCD comprising:
- a plurality of taps, each tap comprising a set of pixels, the CCD being configured to independently adjust an integration time of each tap depending on where the set of pixels of the tap is positioned to collect light scattered from the wafer, the system being configured to allow a user to manually adjust the integration time of each tap depending on where the set of pixels of the tap is collecting light scattered from the wafer.
A system configured to inspect a wafer, the wafer comprising at least two regions that scatter light differently, the system comprising:
- a collector configured to collect light scattered from the wafer, the collector comprising a charge coupled device (CCD), the CCD comprising:
- a plurality of taps, each tap comprising a set of pixels, the CCD being configured to independently adjust an integration time of each tap depending on where the set of pixels of the tap is positioned to collect light scattered from the wafer, the system being configured to automatically adjust the integration time of each tap depending on where the set of pixels of the tap is collecting light scattered from the wafer.
A charge coupled device (CCD) configured to collect light scattered from a surface, the surface comprising at least two regions that scatter light differently, the CCD comprising:
- a plurality of taps, each tap comprising a set of pixels, the CCD being configured to independently adjust an integration time of each tap depending on where the set of pixels of the tap is positioned to collect light scattered from the surface, wherein the integration times of at least two taps positioned to collect light scattered from the at least two regions are different.
A system configured to inspect a surface, the surface comprising at least two regions that scatter light differently, the system comprising:
- a charge coupled device (CCD) configured to collect light scattered from the surface, the CCD comprising:
- a plurality of taps, each tap comprising a set of pixels, the CCD being configured to independently adjust an integration time of each tap depending on where the set of pixels of the tap is positioned to collect light scattered from the surface, wherein the integration times of at least two taps positioned to collect light scattered from the at least two regions are different.
A method of collecting light scattered from a surface, the surface comprising at least two regions that scatter light differently, the method comprising:
- setting integration times for a plurality of taps in a charge coupled device (CCD) according to where pixels of the taps are positioned to collect light scattered from the surface, so that the integration times of at least two taps positioned to collect light scattered from the at least two regions are different;
- and
- collecting light scattered from the surface during the integration times.
A method of collecting light scattered from a surface, the surface comprising at least two regions that scatter light differently, the method comprising:
- setting integration times for a plurality of taps in a charge coupled device (CCD) according to where pixels of the taps are positioned to collect light scattered from the surface;
- manually adjusting the integration time of an individual tap;
- and
- collecting light scattered from the surface during the integration times.
A method of collecting light scattered from a surface, the surface comprising at least two regions that scatter light differently, the method comprising:
- setting integration times for a plurality of taps in a charge coupled device (CCD) according to where pixels of the taps are positioned to collect light scattered from the surface;
- automatically adjusting the integration time of an individual tap;
- and
- collecting light scattered from the surface during the integration times.
A method of collecting light scattered from a surface, the surface comprising at least two regions that scatter light differently, the method comprising:
- setting integration times for a plurality of taps in a charge coupled device (CCD) according to where pixels of the taps are positioned to collect light scattered from the surface, wherein the integration times are adjusted such that the CCD obtains a non-saturated, maximum gray level from different light scattering regions of the surface;
- and
- collecting light scattered from the surface during the integration times.
A method of setting integration times for a plurality of taps in a charge coupled device (CCD), the CCD being configured to scan a surface comprising at least two regions that scatter light differently, the method comprising:
- setting a first integration time for a first tap positioned to collect light scattered from the first region;
- setting a second integration time for a second tap positioned to collect light scattered from the second region, wherein the first integration time is different than the second integration time;
- and
- collecting light scattered from the first and second regions.
A system configured to inspect a surface, the system comprising:
- a charge coupled device (CCD) configured to collect light scattered from the surface, the CCD comprising:
- a plurality of taps, each tap comprising a set of pixels, the CCD being configured to independently adjust an integration time of each tap depending on where the set of pixels of the tap is positioned to collect light scattered from the surface, wherein the integration times of at least two taps positioned to collect light scattered from different regions of the surface are different.
A method of collecting light scattered from a surface, the method comprising:
- setting integration times for a plurality of taps in a charge coupled device (CCD) according to where pixels of the taps are positioned to collect light scattered from the surface, so that the integration times of at least two taps positioned to collect light scattered from different regions of the surface are different;
- and
- collecting light scattered from the surface during the integration times.
Dependencies are inferred from the claim text.