Model-based proximity effect correction for electron-beam direct-write lithography

A model-based proximity effect correction methodology is proposed and tested for electron-beam-direct-write lithography. It iteratively modulates layout geometry by feedback compensation until the correction error converges. The energy intensity distribution is efficiently calculated by fast convolving the modulated layout with a point-spread function which models electron beam shape and proximity effects primarily due to electron scattering in resist. The effectiveness of this methodology is measured by iteration numbers required for meeting the patterning fidelity specifications. It is examined versus process parameters including acceleration voltage and resist thickness with several regular mask geometries and practical design layouts.