Experimental evaluation method of point spread functions used for proximity effects correction in electron beam lithography

The accuracy of the proximity effect correction in electron beam lithography is very dependent on how well the point-spread function used in the correction matches the actual electron scattering effects. A fast and simple technique to evaluate and compare the medium and long-range accuracy of electron scattering point-spread functions is presented. The method is based on the evaluation of the thickness uniformity of partially developed resist inside the proximity corrected pattern by judging the interference color uniformity. It can be applied to almost any pattern design. As an example, three corrected exposures using point-spread functions for semi-insulating GaAs generated by commercial Monte Carlo simulation programs were experimentally evaluated. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3656343]