Lithographic apparatus, analyzer plate, subassembly, method of measuring a parameter of a projection system and patterning device

An analyzer plate comprising:

• a first region arranged to transmit radiation polarized in a first direction, and a second region arranged to transmit radiation polarized in a second direction,
• wherein the first and the second regions cross each other.

A subassembly configured to receive radiation, the subassembly comprising:

• an analyzer plate including a first region arranged to transmit radiation polarized in a first direction and a second region arranged to transmit radiation polarized in a second direction, and
• a radiation sensor arranged to receive the radiation passing through the analyzer plate, wherein the second region crosses the first region.

A method of measuring a parameter of a projection system, wherein the parameter differs in value with a change of polarization state of a beam of radiation that propagates through the projection system, the method comprising:

• patterning a cross section of the beam of radiation, wherein the patterning does not substantially influence the polarization state of the beam of radiation;
• projecting the patterned beam of radiation onto an analyzer plate, the analyzer plate including a first region arranged to transmit radiation polarized in a first direction, and a second region arranged to transmit radiation polarized in a second direction, the second region crossing the first region, said patterned beam of radiation being substantially projected onto the first region of the analyzer plate, and
• measuring an amount of radiation passing through the analyzer plate using a radiation sensor to give a measurement value that includes radiation polarized in the first direction.

A patterning device comprising:

• a first region arranged to substantially transmit a same amount of radiation polarized in any two given directions, and
• a second region arranged to substantially transmit a same amount of radiation polarized in said any two given directions,
• wherein the first region and the second region cross each other.

A patterning device comprising a circuit pattern and a first region arranged to transmit a same amount of radiation polarized in any two given directions.

A method of measuring a polarization state of a beam of radiation in a lithographic apparatus, the method comprising:

• selecting an area of one of a first and a second region of an analyzer plate to be exposed by the beam of radiation, said first region being arranged to transmit radiation polarized in a first direction and said second region being arranged to transmit radiation polarized in a second direction, wherein said first and second regions cross each other;
• substantially projecting the beam of radiation onto the area of said one region of the analyzer plate, and measuring an amount of radiation transmitted through the area of said one region, and
• substantially projecting the beam of radiation onto the other one of said first and second regions of the analyzer plate, and measuring an amount of radiation transmitted through the area of said other one region.