Abstract: An inspection apparatus, including: an optical system configured to provide a beam of radiation to a surface to be measured and to receive redirected radiation from the surface; and a detection system configured to measure the redirected radiation, wherein the optical system includes an optical element to process the radiation, the optical element including a Mac Neille-type multilayer polarizing coating configured to produce a reduced chromatic offset of the radiation.

Abstract: A method of forming an anti-reflection layer, the method including applying a first mixture to an object, the first mixture made from a combination of aluminum tri-sec-butoxide (ATSB), a first chelating agent, water and an alcohol; removing a majority of the alcohol from the applied first mixture; after the removing, applying a second mixture to the object, the second mixture made from a combination of aluminum tri-sec-butoxide, a second chelating agent different than the first chelating agent, water and an alcohol; and removing a majority of the alcohol from the applied second mixture, wherein the applied first and second mixtures are used to form the anti-reflection layer.

Abstract: A substrate provided with an anti-reflective coating where the anti-reflective coating is made up of a layer of nanostructures. The nanostructures may be formed by depositing a material such as SiO2 and then using a process such as reactive ion etching in conjunction with an inductively coupled plasma source. Other aspects of the fabrication process are also disclosed.

Abstract: An inspection apparatus, including: an optical system configured to provide a beam of radiation to a surface to be measured and to receive redirected radiation from the surface; and a detection system configured to measure the redirected radiation, wherein the optical system includes an optical element to process the radiation, the optical element including a Mac Neille-type multilayer polarizing coating configured to produce a reduced chromatic offset of the radiation.

Abstract: A method is disclosed that includes splitting a beam of radiation into a first part of the beam having a first polarization and a second part of the beam having a second polarization, forming a first beam with a first polarization distribution between the first polarization and the second polarization and/or a first intensity distribution by modulating the first part of the beam, forming a second beam with a second polarization distribution between the first polarization and the second polarization and/or a second intensity distribution by modulating the second part of the beam, and combining at least a portion of the first beam having the second polarization and at least a portion of the second beam having the first polarization.

Abstract: A method of forming an anti-reflection layer, the method including applying a first mixture to an object, the first mixture made from a combination of aluminum tri-sec-butoxide (ATSB), a first chelating agent, water and an alcohol; removing a majority of the alcohol from the applied first mixture; after the removing, applying a second mixture to the object, the second mixture made from a combination of aluminum tri-sec-butoxide, a second chelating agent different than the first chelating agent, water and an alcohol; and removing a majority of the alcohol from the applied second mixture, wherein the applied first and second mixtures are used to form the anti-reflection layer.

Abstract: A light combiner (500) for use in a metrology tool includes a plurality of light sources (LED 1, LED 2, LED 3, LED 4, LED 5), a first filter (502), and a second filter (504). The first filter is designed to substantially reflect light generated from a first source of the plurality of light sources, and to substantially transmit light generated from a second source of the plurality of light sources. The second filter is designed to substantially reflect light generated from the first source and the second source of the plurality of light sources, and to substantially transmit light generated from a third source of the plurality of light sources. An angle of incidence of the light generated from the first source on a surface of the first filter is less than 30 degrees.

Abstract: A substrate provided with an anti-reflective coating where the anti-reflective coating is made up of a layer of nanostructures. The nanostructures may be formed by depositing a material such as SiO2 and then using a process such as reactive ion etching in conjunction with an inductively coupled plasma source. Other aspects of the fabrication process ae also disclosed.

Abstract: A method is disclosed that includes splitting a beam of radiation into a first part of the beam having a first polarization and a second part of the beam having a second polarization, forming a first beam with a first polarization distribution between the first polarization and the second polarization and/or a first intensity distribution by modulating the first part of the beam, forming a second beam with a second polarization distribution between the first polarization and the second polarization and/or a second intensity distribution by modulating the second part of the beam, and combining at least a portion of the first beam having the second polarization and at least a portion of the second beam having the first polarization.

Abstract: An optical element including an anti-reflective coating is provided. The optical element includes a silicon substrate and a reflective layer disposed onto a first portion of the surface of the silicon substrate. An anti-reflective layer is disposed onto a second portion of the surface of the silicon substrate such that destructive interference at the anti-reflective layer substantially reduces any reflection of radiation incident on the anti-reflective layer.

Abstract: An optical element including an anti-reflective coating is provided. The optical element includes a silicon substrate and a reflective layer disposed onto a first portion of the surface of the silicon substrate. An anti-reflective layer is disposed onto a second portion of the surface of the silicon substrate such that destructive interference at the anti-reflective layer substantially reduces any reflection of radiation incident on the anti-reflective layer.