Patent ID: 8149378
Filing Date: 2012-04-03
Classification: B82Y,G03F,G21K

Abstract:
1. A cleaning apparatus to clean an optical element included in an exposure apparatus, wherein the exposure apparatus is configured to perform a mask pattern exposure process that utilizes the optical element to at least one of reflect and diffract an exposure light having a pattern of an exposing mask onto a substrate and, as a result of the mask pattern exposure process, contamination is left on the optical element, the cleaning apparatus comprising: an exposure-history recording part configured to record exposure history information, wherein the exposure history information represents a record of exposure light projected onto one or more substrates from a set of substrates; a setting unit configured to set a plurality of regions in a predetermined cleaning area of the optical element; a cleaning-light-amount analyzing part configured to utilize the exposure history information to calculate information on a cumulative light amount distribution of a cleaning light (CLADcl) to be irradiated onto each region; and a signal generation unit configured to generate a signal configured to cause a cleaning light system to apply the cleaning light to each region to remove contamination from the optical element, wherein the cleaning light includes a wavelength that is different from a wavelength of the exposure light, and wherein the amount of cleaning light irradiated onto each region is a function of the calculated cumulative light amount distribution of the cleaning light (CLADcl) such that each region receives enough cleaning light to remove contamination from a surface of the optical element while avoiding deteriorating that surface through excessive cleaning light and without directly researching a deposition state of contamination on the optical element, wherein the exposure history information includes, as information elements, at least one of (i) a pattern of an exposing mask, (ii) irradiation conditions of the exposure light that include at least one of the intensity of the exposure light and the amount of the exposure light, and (iii) atmosphere of a space bound by a projection optical system that includes the optical element, wherein the atmosphere is represented at least by a partial pressure, and wherein, in a case where the information on a cumulative light amount distribution of the cleaning light is calculated to within predetermined accuracy, the recording part records only one information element.