Abstract:
A method (500) for cleaning an article such as a EUV (extreme ultraviolet) lithography reticle is provided. The method includes evacuating a cleaning chamber and loading the article to be cleaned into the cleaning chamber (510); preparing the environment of the chamber (520) by connecting the cleaning chamber to a vapor source while controlling pressure in the cleaning chamber to a predetermined pressure; controlling a temperature of the article relative to a temperature of the vapor source so as to form a liquid film (530) over the article and over particles present on the article; isolating the cleaning chamber from the vapor source; evaporating the liquid film (540) by exposing the cleaning chamber to one or more condensing surfaces whose temperature is lower than that of the article, the evaporating liquid transporting at least a portion of the particles away from the article, which is then unloaded from the chamber (560). The cleaning steps (520 to 540) can be repeated (550) as desired.
Abstract:
A lithographic apparatus includes an illumination system configured to condition a beam of radiation, and a support structure configured to support a patterning device. The patterning device is configured to impart a pattern to the beam of radiation. The apparatus includes a patterning device cleaning system configured to provide an electrostatic force to contaminant particles that are on the patterning device and that are electrically charged by the beam of radiation, in order to remove the contaminant particles from the patterning device.
Abstract:
A method according to an embodiment includes obtaining calibration measurement data, with an optical detection apparatus, from a plurality of marker structure sets provided on a calibration substrate. Each marker structure set includes at least one calibration marker structure created using different known values of the process parameter. The method includes obtaining measurement data, with the optical detection apparatus, from at least on marker structure provided on a substrate and exposed using an unknown value of the process parameter; and determining the unknown value of the process parameter from the obtained measurement data by employing regression coefficients in a model based on the known values of the process parameter and the calibration measurement data.