The EUV projection glass lens which has the mirror which is formed with the material where the code of the gradient for the rise of temperature according to the coefficient of thermal expansion around zero transition temperatures differs

摘要

A projection objective 1 for short wavelengths and in particular for wavelengths lambda157 nm is provided with a number of mirrors [M1, M2, M3, M4 and M5 and M6] that are arranged positioned precisely in relation to an optical axis 5. The mirrors [M1, M2, M3, M4 and M5 and M6] have multilayer coatings. At least two different mirror materials are provided which differ in the rise in the coefficient of thermal expansion as a function of temperature in the region of the zero crossing of the coefficients of thermal expansion and in particular in the sign of the size.