关键词: 差动莫尔信号, 超高精度对正, 结构光栅, 压印光刻

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 detec-tors then the detected signals are used to estimate the magnit-udes of misalignment in x, y directions. The test results confo-rmed 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: Differential moiré signal, Grating, Imprint lithography, Ultra-precision alignment