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Two main challenges of future mask making are the decreasing throughput of the pattern generators and the insufficient
line edge roughness of the resist structures. The increasing design complexity with smaller feature sizes combined with
additional pattern elements of the Optical Proximity Correction generates huge data volumes which reduce
correspondingly the throughput of conventional single e-beam pattern generators. On the other hand the achievable line
edge roughness when using sensitive chemically amplified resists does not fulfill the future requirements. The
application of less sensitive resists may provide an improved roughness, however on account of throughput, as well. To
overcome this challenge a proton multi-beam pattern generator is developed [1]. Starting with a highly parallel broad
beam, an aperture-plate is used to generate thousands of separate spot beams. These beams pass through a blanking-plate
unit, based on a CMOS device for de-multiplexing the writing data and equipped with electrodes placed around the
apertures switching the beams "on" or "off", dependent on the desired pattern. The beam array is demagnified by a 200x
reduction optics and the exposure of the entire substrate is done by a continuous moving stage.
One major challenge is the fabrication of the required high aspect deflection electrodes and their connection to the
CMOS device. One approach is to combine a post-processed CMOS chip with a MEMS component containing the
deflection electrodes and to realize the electrical connection of both by vertical integration techniques. For the evaluation
and assessment of this considered scheme and fabrication technique, a proof-of-concept deflection unit has been realized
and tested. Our design is based on the generation of the deflection electrodes in a silicon membrane by etching trenches
and oxide filling afterwards. In a 5mm x 5mm area 43,000 apertures with the corresponding electrodes have been
structured and wired individually or in groups with aluminum lines. The aperture-plate for shaping the beams has been
aligned and mounted on top of the blanking-plate. Afterwards this sandwich has been fixed on a base-plate with a pin
plug as interface. The electrical connection has been performed with a standard chip bonding process to the aluminum
pads on the blanking-plate. Finally, the proof-of-concept deflection unit was evaluated in a test bench. The results of
electrical- and exposure tests are presented and discussed in detail.
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