| Electron beam lithography machine is the key instrument for mask making and research of nanometer device. The width of the finest line is 5nm in e-beam lithography. Modified electron beam lithography machine based on scanning electron microscope (SEM) has great future in lab and university for its low price and flexibility. But small deflection field less than 100 micrometer resulted in low productivity. Enlarging deflection field, using higher bright cathode, higher speed stage and higher sensitive resist can effectively solve the problem, among which enlarging the field is the most potential. System aberrations are sure to increase with deflection field enlarging only. So research on low aberrations, large deflection field and nanometer scale focusing deflection system has become urgent at present. Two parts are included as follows. (1) Optimum design of nanometer-scale focusing deflection based on JSM-35CF SEM and related research. With the aid of the advanced electron-optics software developed by Munro's Ltd., field distribution is calculated accurately by second-order finite element method and optical column is optimized by damped least squares method. Optimum variables are the position, relative rotated angle and relative strengths of deflectors. Fifth-order aberrations and lading angle are chosen as the objective. Through changing positions, relative rotated angle, and relative strengths of the deflectors, deflection field, which suit for nanometer exposure, is expanded to 250 micrometer. Some deflectors, which can eliminate four-fold aberrations, are compared in sensitivity and performance. It is found that system with two deflectors in different length has highest sensitivity in the pre-lens double deflection system, when the value of optimum relative strength is...
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