The first Aerial Image Measurement System (AIMS™) (1) for 157 nm lithography worldwide has been brought into operation successfully. Due to the wavelength in the vacuum ultraviolet (VUV) spectrum major efforts had been required for the illumination and imaging part of the optical components as well as for the purging of the system which will be discussed. The system's performance will be demonstrated by AIMS™ measurements at 157 nm wavelength on binary chrome photomasks. Several through focus series have been measured in order to evaluate transmission, linewidth (CD) results, Bossung curves and to calculate the exposure-defocus windows. Detailed results of short-term and long-term CD repeatability measurements are discussed which prove the usage of the system for mask evaluation for 157nm lithography. Measurements of mask structures with feature sizes at mask level of 240 nm will be presented and discussed.
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