Method and apparatus for protecting surfaces of optical components
AssigneeKLA-Tencor Technologies Corporation
InventorsGil Delgado, John McMurtry, James Wiley
Life of this patent
Estimating the term…
Abstract
The invention pertains to mechanisms for protecting surfaces of optical components of an optical inspection system. One aspect of the invention relates to a gas purge system that produces a gas stream that blocks contaminants from reaching the optical surfaces of the optical components and that transports contaminants away from the optical surfaces of the optical components. Another aspect of the invention relates to a transparent cover that physically blocks contaminants from reaching the optical surfaces of the optical components. Yet another aspect of the invention relates to a combination of the gas purge system and the transparent cover.
Claims31
An inspection system for detecting defects on a sample, the inspection system comprising:
- an optical subsystem configured to collect ultra violet light emanating from the sample, the optical subsystem including an optical component having an optical surface;
- a detector configured to receive the collected light from the optical subsystem and to generate an image of at least a portion of the sample with the received light;
- an analyzer configured to determine whether there are any defects present on the portion of the sample by analyzing the image generated by the detector;
- and
- a gas purge system configured to produce a gas stream that blocks contaminants from reaching the optical surface of the optical component and that transports the contaminants away from the optical surface of the optical component, the gas purge system including a substantially planar cover having an opening disposed in front of and along an optical axis of the optical component, the opening allowing light to pass for the purpose of inspecting the optical surface of the optical component, and the gas stream to pass for the purpose of preventing contaminants from reaching the optical surface of the optical component.
A system for inspecting substrates, comprising:
- an optical subsystem having a front lens;
- and
- a cover disposed between the front lens and the substrate to be inspected, the cover having an opening that allows ultra violet light to pass between the front lens and the substrate to be inspected, the cover defining at least in part a channel within in which a gas stream is created for the purpose of preventing particles from depositing on the front lens.
A gas flow system for an optical inspection system, the gas flow system comprising:
- a means for flowing a gas stream in front of an exposed optical surface of the optical inspection system so as to prevent contaminants from adversely effecting the exposed optical surface of the optical inspection system,
- wherein the gas stream is routed across the exposed optical surface substantially transverse to the optical axis of the exposed optical surface.
A gas flow system for an optical inspections system, the gas flow system comprising:
- a means for flowing a gas stream in from of an exposed optical surface of the optical inspection system so as to prevent contaminants from adversely effecting the exposed optical surface of the optical inspection system,
- wherein the gas stream is routed away from the exposed optical surface substantially parallel to the optical axis of the optical surface.
An optical inspection system for inspecting a semiconductor surface for defects or other abnormalities thereof, comprising:
- an optical subsystem configured to collect light emanating from the semiconductor surface and to direct the collected light to a detector, the optical subsystem including a series of optical components a lens disposed along an optical path, the series of optical components including a front collection lens that is the optical component closest to the semiconductor surface;
- and
- a transparent cover disposed proximately to the front collection lens between the front collection lens and the semiconductor surface to protect the front collection lens from contamination.
A gas flow system for an optical inspection system, the gas flow system comprising:
- a means for flowing a gas stream in front of an exposed optical surface of the optical inspection system so as to prevent contaminants from adversely effecting the exposed optical surface of the optical inspection system,
- wherein the optical inspection system includes an optical subsystem having a plurality of optical components aligned along an optical axis, the optical components cooperating to collect light emanating from a sample and to direct the collected list to a detector for the purpose of defect analysis, and wherein the exposed optical surface is from at least one of the optical components of the optical inspection system, and
- wherein the gas steam flows at least in part parallel to the exposed surface.
Dependencies are inferred from the claim text.