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Abstract: An ultra-precision alignment technique based on
differential moiré technique is presented for room- temperature imprint
lithography. The Moiré signal generated by a pair of special slant
gratings is detected by a set of photoelectric detectors then the
detected signals are used to estimate the magnitudes of misalignment in
x, y directions. The test results conformed that differential moiré
signal is more sensitive than simple moiré signal. Additionally, a
Chebyshev digital filter is adopted in control system to reduce the
noise from the differential moiré signals. As a result, the repeatable
alignment accuracy can reach ±20 nm and meet the requirement of
alignment accuracy for sub-100 nm imprint lithography.
Key words:
Imprint lithography Grating Differential moiré signal
Ultra-precision alignment
CLC No: TH74
TN247
国家自然科学基金
(50275118)、国家863计划重点(2002AA420050)和国家重点基础研究发展计划(2003CB716203)资助项目.
Received 20040621, received in revised form 20050110
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