Li Zhu*, Jie Liu, Xinbin Cheng, Tongbao Li and Xiao Deng Pages 1 - 5 ( 5 )
Background: As progress on the nanofabrication has made semiconductor developed rapidly, there is an increasing need in precise pitch standards to calibrate the structure of devices at nanoscale. Nano-gratings fabricated by atom lithography are unique and suitable to act as precise pitch standard because its pitch distance is directly traceable to a natural constant. As the scaling down of nano-devices, it is very challenging to double the spatial frequency of nano-grating while keeping the self-traceability in atom lithography. Methods: In this study, the switching-detuning light mask is utilized for Cr atom lithography. During a single deposition process, the standing wave frequency is switching from positive detuning to negative detuning alternatively. Results: Nano-gratings fabricated using switching-detuning light mask is successfully replicated with double spatial frequency and self-traceability. Non-uniformity between neighboring Cr lines shows up with a corrected pitch of 107.15±0.35 nm. Conclusion: Non-uniformity is mainly caused by the dipole force discrepancy between positive and negative detuning light mask. Therefore, to increase the high uniformity of nano-gratings, the deposition time of negative detuning should be at least twice as long as positive detuning. On the other hand, to reduce the pitch uncertainty, it is necessary to reduce the distance between the atom beam and reflection mirror as close as possible. These two significant optimization designs are promising to increase the spatial frequency doubling performance with high uniformity and accuracy.
Atom lithography, Standard material, Self-traceability, Double spatial frequency, Height uniformity, Pitch accuracy
Tongji University, School of Physics Science and Engineering, 1239 Siping Rd, Yangpu Dist, Shanghai 200092, Tongji University, School of Physics Science and Engineering, Tongji University School of Physics Science and Engineering, Tongji University, School of Physics Science and Engineering, Tongji University, School of Aerospace Engineering and Applied Mechanics