Beam shaping of excimer laser used for lithography and its research progress

The causes for beam-shaping of excimer laser in the application of lithography and the results of the beam spatial intensity profiles before and after shaping are expounded.The method of theoretical modeling—Gaussian-Schell model built-up for beam-shaping of excimer is also introduced.The advantages and defects,including the shaping capability,the energy loss,the interference effect,the control of wavefront and uniform distribution of amplitude, etc.,of beam-homogenizer such as microlens array and diffractive phase grating and so on used for lithographic beam-shaping are summarized and analyzed.Moreover,the principles, characteristics and progress of the beamshaper are brief reviewed.