A 100-kV, 100-A/cm/sup 2/ electron optical system for the EB-X3 X-ray mask writer

In order to fabricate high-quality x-ray masks, we developed the EB-X3, a variably shaped electron beam writing system (beam voltage:100 kV; current density:50 PJcm/sup 2/; patterning resolution:50 nm). It currently has an image placement accuracy of less than 15 nm (3/spl omega/) and critical dimension control of less than 10 nm (3/spl omega/), and efforts to improve the accuracy are continuing. The fabrication of x-ray masks with a ground rule of less than 100 nm requires not only improvement of the resolution and accuracy, but improvement of the throughput as well. In order to increase throughput, we have devised a way to increase the current density of the EB-X3, and verified its effectiveness through experiments.