An electron-beam lithography system for fabricating optical elements, and patterning-error analysis by the finite-element method

摘要

A concentric circle pattern with an accuracy of 0.1 mu m and a circle pattern of diameter 60 mm have been fabricated under a fixed electron beam. Using the newly developed specimen stage, a positioning accuracy of 0.01 mu m of the linear stage and a rotation error of 0.05 mu mp-pof the rotary stage have also been obtained. However, there is the problem of patterning errors due to the reactive magnetic field of the eddy current on the rotary stage. A finite-element method magnetic-field analysis has been applied to determine the level of patterning errors. As a result of the simulation, the patterning errors amount to 1*10-5mu m under a rotation of 1000 rpm using a semiconductive specimen holder on the rotary stage, and 470 mu m using an aluminum specimen holder. In practice 100 k Omega cm SiC ceramics are used for the specimen holder.