Differential wavelength inspection system
AssigneeAdvanced Micro Devices, Inc.
InventorsBruno M. La Fontaine, Harry J. Levinson, Jeffrey A. Schefske
Life of this patent
Estimating the term…
Abstract
An inspection tool or inspection system can be utilized to determine whether the appropriate pattern is on a reticle. The reticle can be associated with EUV lithographic tools. The system utilizes at least two wavelengths of light. The light is directed to the reticle at the at least two wavelengths of light and detected by a detector. The image associated with the first wavelength is subtracted from or otherwise processed with respect to the image associated with the second wavelength to improve contrast ratio.
Claims20
An inspection system for a reticle including a multilayer and an absorbing pattern, the inspection system comprising:
- a light source;
- and
- a detector, wherein the light source sequentially provides light at a first wavelength and at a second wavelength, wherein the detector is positioned to receive the light at the first wavelength and the light at the second wavelength after the light is reflected off the reticle, wherein the absorbing pattern has similar reflective characteristics at the first and second wavelengths and the multilayer portion has different reflective characteristics at the first and second wavelengths or wherein the absorbing pattern has different reflective characteristics at the first and second wavelengths and the multilayer portion has similar reflective characteristics at the first and second wavelength, whereby the light at the first and second wavelengths is processed to increase contrast ratio.
A method of inspecting a reticle associated with manufacture of an integrated circuit, the method comprising:
- providing radiation at a first wavelength to the reticle;
- receiving the radiation at the first wavelength reflected from the reticle surface;
- providing radiation at a second wavelength to the reticle;
- and
- receiving the radiation at the second wavelength reflected from the reticle, wherein the absorbing portion has similar reflective characteristics at the first and second wavelengths and the reflective portion has different reflective characteristics at the first and second wavelengths.
A method of inspecting a reticle associated with manufacture of an integrated circuit, the method comprising:
- providing radiation at a first wavelength to the reticle;
- receiving the radiation at the first wavelength reflected from the reticle surface;
- providing radiation at a second wavelength to the reticle;
- and
- receiving the radiation at the second wavelength reflected from the reticle,
- wherein the absorbing portion has different reflective characteristics at the first and second wavelength and the reflective portion has similar reflective characteristics at the first and second wavelengths.
An inspection system for an EUV reticle for use in an integrated circuit fabrication system, the inspection system comprising:
- means for providing radiation at a first wavelength to the reticle;
- means for providing radiation at a second wavelength to the reticle;
- means for detecting the radiation at the first wavelength and the radiation at the second wavelength;
- and
- means for comparing the reflected radiation at the first wavelength to the reflected radiation at the second wavelength,
- wherein the reticle includes an absorber and a reflector, the absorber having different reflective characteristics at the first and second wavelengths, the reflector having similar reflective characteristics at the first and second wavelengths.
An inspection system for an EUV reticle for use in an integrated circuit fabrication system, the inspection system comprising:
- means for providing radiation at a first wavelength to the reticle;
- means for providing radiation at a second wavelength to the reticle;
- means for detecting the radiation at the first wavelength and the radiation at the second wavelength;
- and
- means for comparing the reflected radiation at the first wavelength to the reflected radiation at the second wavelength;
- wherein the reticle includes an absorber and a reflector, the absorber having similar reflective characteristics at the first and second wavelengths and the reflector having different reflective characteristics at the first and second wavelengths.
Dependencies are inferred from the claim text.