The limitations to the throughput of electron beam systems employing a single axis are now well known. Accordingly there is increased activity in the exploration of multiaxis systems. The approach described here features both common focusing and common deflection, thus simplifying the problem of pattern stitching. Another feature, thought by some to be a disadvantage, is that the imaging is at unity magnification. We have designed and built a test stand that presently features one axis (or beamlet) in a large homogeneous magnetic field so that the extension to multiple axes can be seen to be straightforward. With this arrangement we have demonstrated that the resolution can be at least in the 30–50 nm range, that operation at low voltage (down to 260 V) is possible, that we can operate using multiple axes, and that secondary electrons generated by one beamlet can be confined so that it is possible to use this arrangement for high-speed inspection.

Articles you may be interested inSimple technique for beam focusing in electron beam lithography on optically transparent substrates Demagnifying immersion magnetic lenses used for projection electron beam lithography without crossovers Variable axis lens of mixed electrostatic and magnetic fields and its application in electron-beam lithography systems J.

An EGS4 Monte Carlo examination of the response of a PTW-diamond radiation detector in megavoltage electron beams Med.The attractiveness of electron beam systems would be greatly enhanced if the throughput could be improved. One approach, described previously by the authors employs a uniform axial magnetic field to focus thousands of electron beams simultaneously ͓D. S. Pickard et al., J. Vac. Sci. Technol. B 21, 2709 ͑2003͒; T. R. Groves and R. A. Kendall, ibid., 16, 3168 ͑1998͔͒. The beamlets never combine to form a common crossover, thereby avoiding the throughput limitations due to space charge blurring. With this approach, one challenge was to fashion a detection scheme that maintains a tight beamlet packing density ͑250 m pitch͒ while minimizing cross-talk between adjacent secondary electron signals, either by crossing trajectories or within the detector. A pin-diode-based detector was investigated as a potential component of the multielement detection scheme for the authors' system. The detector features a two-dimensional array of elements on high resistivity float-zone silicon. The detector attributes that were attractive to their application include modest internal amplification ͑Ͼ5000 at 25 kV͒, fast response time ͑measured at Ͻ10 ns͒, ability to be made compact and with dense packed electrodes ͑Ͻ250 m͒, low electrode capacitance ͑Ͻ1 pF͒, and ability for ͑complementary metal-oxide semiconductor͒ circuitry to be integrated directly onto the detector array so that low noise amplification of each signal can be performed. This detector requires a retarding field for the primary beam, which accelerates the secondary electrons to energies sufficient to excite a large number of internal secondaries.

Scaled measurements of global space-charge induced image blur in electron beam projection systemVariable axis lens of mixed electrostatic and magnetic fields and its application in electron-beam lithography systems J.