Reflective optical element and exposure apparatus

Abstract

An exposure apparatus includes (A) an illumination optical system that illuminates a reticle with illumination light from a light source, and (B) a projection optical system that includes a reflective optical element and projects a pattern of the reticle onto a member to be processed to expose the member. The reflective optical element includes (a) a base member, and (b) a dielectric multilayer film laminated on the base member. The dielectric multilayer film includes, in an order from a base member side, (i) a first multilayer group that is constituted by laminating at least four dielectric material layers, which includes at least two dielectric material layers having different refractive indices from each other and that has a first period length equivalent in optical film thickness, and (ii) a second multilayer group that is constituted by laminating at least four dielectric material layers, which includes at least two dielectric material layers having different refractive indices from each other and that has a second period length equivalent in optical film thickness longer than the first period length equivalent in optical film thickness. The dielectric multilayer films include a plurality of pairs of the first and second multilayer groups.