Patent ID: 7787103
Filing Date: 2010-08-31
Classification: G03B,G03F

Abstract:
1. A protection exposure apparatus comprising: a protection optical system configured to project a pattern image of an original onto a substrate; an original stage configured to hold the original; a substrate stage configured to hold the substrate; and a measurement unit, wherein said measurement unit includes a Fizeau interferometer including a first optical unit mounted on said original stage and a mirror mounted on said substrate stage, said first optical unit including a first lens having a Fizeau surface which is not coated with any antireflection coating and which is configured to split a light beam into a reference light beam and a test light beam, and said mirror being configured to reflect the test light beam having passed through said projection optical system, and wherein said measurement unit further comprises a second optical unit including a second lens which has a shape identical to a shape of said first lens and has a surface which opposes said projection optical system and is coated with an antireflection coating.