Patent ID: 8572522
Filing Date: 2013-10-29
Classification: G03F

Abstract:
1. A method for determining lithographic processing conditions for a lithographic process, the method comprising: performing using a processing system: obtaining characteristics of an illumination source and a mask design, the mask design comprising a lithography pattern; performing a first optimization for combined optimizing of at least the illumination source characteristics and the mask design characteristics for the lithographic process, whereby for the first optimization non-rectangular sub-resolution assist features for the mask are allowed; determining from the first optimization a set of optimized illumination source characteristics; performing at least one additional optimization for optimizing the mask design characteristics of the lithographic process, whereby for the at least one additional optimization the presence of non-rectangular sub-resolution assist features for the mask design is substantially excluded and whereby the at least one additional optimization takes into account the set of optimized illumination source characteristics; and determining from the at least one additional optimization a set of optimized mask design characteristics substantially excluding non-rectangular sub-resolution assist features.