Multiaxis and multibeam technology for high throughput maskless E-beam lithography

The authors have devised a new maskless E-beam lithography method which can achieve a throughput of 10 wph which the authors are calling a “multiaxis programmable shaped beam” (multiaxis PSB). It is a kind of massive parallel electron beam lithography wherein more than 250 000 beams write a wafer and the total beam current reaches a hundred microamperes. It may be difficult to write a pattern finer than 10 nm with more than 1 μA beam current at 50 kV with a single column because of blurring from Coulomb interaction, so the multiaxis PSB system divides all the beams into 87 groups where each group has 2500–10 000 beams formed by a small column arrayed in a 26 × 33 mm2 lattice. The small column is called a column element (CE) and each CE has an emitter, apertures, deflectors, and small lenses. The key technologies of the multiaxis system are a lens, emitter, and blankers for individual beamlets. The authors have proposed new ideas for these issues and made fundamental experiments.