研究目的
To push the limit of minimum linewidth in STED direct laser writing to sub-50 nm dimension using a rod-shape effective focus spot.
研究成果
A stable and continuous nanowire with 45 nm width was achieved, which is λ/18 of the excitation wavelength and the thinnest in PETA photoresist. This method accelerates the progress of precision enhancement in optical nanofabrication.
研究不足
The method requires precise control of laser powers and alignment. Higher depletion power can lead to unstable or discontinuous nanowires.
1：Experimental Design and Method Selection
STED direct laser writing with a rod-shape effective focus spot, combining a Gaussian excitation focus and twin-oval depletion focus.
2：Sample Selection and Data Sources
Pentaerythritol triacrylate (PETA) photoresist with different photoinitiators (DETC and ITX).
3：List of Experimental Equipment and Materials
Ti: sapphire femtosecond laser (Micra-10, Coherent Inc.), 532 nm continuous-wave laser (Millennia Pro, Spectra-Physics Laser Inc.), 100× oil immersion objective lens (Apo TIRE, Nikon Co.), cover slice (12-540A, Fisherbrand), three-axis piezo-electric stage (P563, Physik Instrumente Co.), optical microscope (Eclipse Ti-U, Nikon), CCD camera (INFINITY1-2CB, Lumenera Co.), field emission scanning electron microscope (Hitachi S-4800, Hitachi Ltd.), atomic force microscope (Auto probe CP, Thermo-Microscopes).
4：Experimental Procedures and Operational Workflow
Laser beams were focused into the photoresist, with the excitation and depletion beams overlapping to form a rod-shaped effective focus spot. The photoresist was developed and analyzed using SEM and AFM.
5：Data Analysis Methods
Width of nanowires measured with imaging software and SEM images. AFM used for height profile analysis.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容-
Ti: sapphire femtosecond laser
Micra-10
Coherent Inc.
Excitation source for STED direct laser writing
-
Field emission scanning electron microscope
Hitachi S-4800
Hitachi Ltd.
Observing the surface topography of the samples
-
532 nm continuous-wave laser
Millennia Pro
Spectra-Physics Laser Inc.
Depletion source for STED direct laser writing
-
100× oil immersion objective lens
Apo TIRE
Nikon Co.
Focusing laser beams into the photoresist
-
Atomic force microscope
Auto probe CP
Thermo-Microscopes
Getting the AFM images and height profile of nanostructures
-
登录查看剩余3件设备及参数对照表
查看全部
