Measurement of wave-front aberrations in high-resolution optical lithographic systems from printed photoresist patterns

A new method of measurement of wave-front aberrations in high-resolution optical lithographic systems used for semiconductor manufacturing is proposed. The method is based on the measurement of the positional shifts and focus offsets of a set of printed photoresist grating patterns with different periods and orientations, produced under nearly fully coherent illumination condition. The proposed experimental procedures are described in detail and various sources of systematic and random errors are discussed. It is estimated that a measurement precision of /spl lambda//50 for the wave-front aberrations at selected points on the lens pupil can be achieved with this method.