Electron beam nanolithographic system having a multiple-beam electron source capable of multiplex control and made from MIM (metal-insulator-metal) thin-film cathodes

摘要

The invention relates to an electron lithography system having a multiple-beam electron source capable of multiplex control and consisting of MIM (metal-insulator-metal) thin-film cathodes. The electrons emitted from a MIM cathode array as multibeam electron source are accelerated by a perforated anode, and the cathode array is projected with the aid of an electron optical reducing system onto the substrate to be exposed. The result by comparison with the electron lithography systems having only one electron beam source is that a larger throughput of substrates to be exposed is possible. The spherical error in the electron optics which occurs in the case of the reduction of relatively large object fields is corrected due to the fact that the MIM cathodes of the cathode array which are situated remote from the electron optical axis emit faster electrons due to the application of a larger operating voltage than do the MIM cathodes near the axis.