Method of evaluating optical element
AssigneeCanon Kabushiki Kaisha
InventorAkira Miyake
Life of this patent
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Abstract
There is provided an evaluation method of a reflective optical element on which a multilayer film is formed, including the step of calculating a phase difference between light incident upon the multilayer film and light reflected from the multilayer film using a standing wave produced when introducing light with a wavelength of 2 to 40 into the optical element.
Claims13
An evaluation method for a reflective optical element on which a multilayer coating is formed, said method comprising the steps of:
- measuring a secondary radiation emitted from the multilayer coating when light with a wavelength of 2 to 40 nm is introduced into the optical element;
- calculating a phase difference between the light incident on the multilayer coating and light reflected from the multilayer coating, based on a result of said measuring the secondary radiation emitted from the multilayer;
- and
- evaluating an equivalent surface shape of the multilayer coating based on a result of said calculating step.
An evaluation method for a reflective optical element on which a multilayer coating is formed, said method comprising the steps of:
- applying a resist onto a surface of the multilayer coating;
- introducing light with a wavelength of 2 to 40 nm into the multilayer coating to which the resist is applied, and exposing the resist;
- measuring a residual coating distribution of the exposed resist;
- calculating a phase difference between the light incident on the multilayer coating and light reflected from the multilayer coating, based on a result of said measuring the residual coating distribution of the exposed resist;
- and
- evaluating an equivalent surface shape of the multilayer coating based on a result of said calculating step.
An evaluation apparatus of a reflective optical element on which a multilayer coating is formed, said evaluation apparatus comprising:
- an illumination optical system for introducing light with a wavelength of 2 to 40 ran into the multilayer coating;
- a detector for detecting a secondary radiation emitted from the multilayer coating;
- and
- a calculator for calculating a phase difference between the light incident on the multilayer coating and light reflected from the multilayer coating, based on a detection result of said detector for detecting a secondary radiation emitted from the multilayer coating.
An evaluation method for a reflective optical element on which a multilayer coating is formed, said method comprising the steps of:
- measuring a secondary radiation consisting of fluorescent X-ray or photoelectrons emitted from the multilayer coating when light with a wavelength of 2 to 40 nm is introduced into the optical element;
- calculating a phase difference between the light incident on the multilayer coating and light reflected from the multilayer coating, based on a result of said measuring the secondary radiation consisting of fluorescent X-ray or photoelectrons emitted from the multilayer;
- and
- evaluating an equivalent surface shape of the multilayer coating based on a result of said calculating step.
Dependencies are inferred from the claim text.