Patent ID: 7426012

Claim:
A method for monitoring parameters of an exposure device for immersion lithography, comprising: providing a semiconductor wafer including a resist layer applied on a front side of the semiconductor wafer; providing an exposure device including at least one nozzle and a lens to project a pattern arranged on a mask into a projection image field on the resist layer; providing a substrate holder configured to accommodate the semiconductor wafer in the exposure device; placing the semiconductor wafer on the substrate holder; spraying a front side of the resist layer on the semiconductor wafer with an immersion liquid via the at least one nozzle such that, above the projection image field, a region between the resist layer and the lens is completely filled with the immersion liquid; successively projecting the pattern arranged on the mask into a plurality of exposure fields of the semiconductor wafer; providing an analysis device configured to determine a plurality of parameters including a frequency and size of microbubbles in the immersion liquid and at least one further parameter of the immersion liquid during the successive projection; providing a desired value for each parameter; comparing the plurality of parameters with associated desired values; and triggering a warning signal on the basis of at least one deviation of at least one parameter of the immersion liquid from an associated desired value.