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Low terahertz-band scanning near-field microscope with 155-nm resolution
Dai, Guangbin1,2,3; Wang, Jie2; Zhang, Xiaoxuan2; Chang, Tianying2; Cui, Hong-Liang1,2
2021-07-01
摘要We report on the design and implementation of a scattering-type scanning near-field microscope working in the low terahertz-band under ambient conditions for nanoscopic investigations of physical properties and characteristics at sample surfaces and interfaces in the microwave and millimeter wave bands. Employing a nano-tip that oscillates vertically at a frequency Omega as the antenna, and a subharmonic mixer as the receiver, and corresponding demodulation algorithms, the back-scattered light carrying tip-sample interaction information is effectively extracted, while excluding almost all of the background noises. The amplitude and phase images constructed from signals demodulated at various harmonics (n Omega, n = 1 - 4) are obtained while scanning an Au-Si step structure with the newly developed microscope, and a resolution of 155 nm (similar to lambda/20,000) has been demonstrated at the fourth harmonic frequency (4 Omega) working at 110 GHz, with signal-to-noise ratio (SNR) equal to 44.4 dB on the Au surface and 36.2 dB on the Si surface, demonstrating the power of this new instrument for micro/nano-resolution studies in the millimeter wave band.
关键词Low terahertz-band Near-field Background scattering Antenna theory Mixer demodulation
DOI10.1016/j.ultramic.2021.113295
发表期刊ULTRAMICROSCOPY
ISSN0304-3991
卷号226页码:7
通讯作者Dai, Guangbin(daiguang@ustc.edu.cn) ; Chang, Tianying(tchang@jlu.edu.cn)
收录类别SCI
WOS记录号WOS:000661167900002
语种英语