scholarly journals Characterization of Line Nanopatterns on Positive Photoresist Produced by Scanning Near-Field Optical Microscope

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Sadegh Mehdi Aghaei ◽  
Navid Yasrebi ◽  
Bizhan Rashidian
Keyword(s):  
Continuous Wave ◽  
Near Field ◽  
Scanning Speed ◽  
Optical Microscope ◽  
Neutral Density Filter ◽  
Sem Images ◽  
Minimum Width ◽  
Positive Photoresist ◽  
Density Filter ◽  
Shear Force Microscopy

Line nanopatterns are produced on the positive photoresist by scanning near-field optical microscope (SNOM). A laser diode with a wavelength of 450 nm and a power of 250 mW as the light source and an aluminum coated nanoprobe with a 70 nm aperture at the tip apex have been employed. A neutral density filter has been used to control the exposure power of the photoresist. It is found that the changes induced by light in the photoresist can be detected byin situshear force microscopy (ShFM), before the development of the photoresist. Scanning electron microscope (SEM) images of the developed photoresist have been used to optimize the scanning speed and the power required for exposure, in order to minimize the final line width. It is shown that nanometric lines with a minimum width of 33 nm can be achieved with a scanning speed of 75 µm/s and a laser power of 113 mW. It is also revealed that the overexposure of the photoresist by continuous wave laser generated heat can be prevented by means of proper photoresist selection. In addition, the effects of multiple exposures of nanopatterns on their width and depth are investigated.

scholarly journals Formation and Characterization of Hole Nanopattern on Photoresist Layer by Scanning Near-Field Optical Microscope

Nanomaterials ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1452
Author(s):  
Agata Roszkiewicz ◽  
Amrita Jain ◽  
Marian Teodorczyk ◽  
Wojciech Nasalski
Keyword(s):  
Quartz Substrate ◽  
Near Field ◽  
Sleep Time ◽  
Optical Microscope ◽  
Phase Zone ◽  
Positive Photoresist ◽  
Photoresist Layer ◽  
532 Nm ◽  
Rigorous Method

Patterning of lines of holes on a layer of positive photoresist SX AR-P 3500/6 (Allresist GmbH, Strausberg, Germany) spin-coated on a quartz substrate is carried out by using scanning near-field optical lithography. A green 532 nm-wavelength laser, focused on a backside of a nanoprobe of 90 nm diameter, is used as a light source. As a result, after optimization of parameters like laser power, exposure time, or sleep time, it is confirmed that it is possible to obtain a uniform nanopattern structure in the photoresist layer. In addition, the lines of holes are characterized by a uniform depth (71–87 nm) and relatively high aspect ratio ranging from 0.22 to 0.26. Numerical modelling performed with a rigorous method shows that such a structure can be potentially used as a phase zone plate.

Near-field scanning optical microscopy

1986 ◽  
Vol 44 ◽  
pp. 642-643
Author(s):  
E. Betzig ◽  
A. Harootunian ◽  
M. Isaacson ◽  
A. Lewis
Keyword(s):  
Near Field ◽  
Optical Microscope ◽  
Visible Radiation ◽  
Field Methods ◽  
Optical Elements ◽  
Optical Region ◽  
Order Of Magnitude ◽  
Nondestructive Imaging ◽  
Scanning Optical Microscopy ◽  
Near Field Scanning

In general, conventional methods of optical imaging are limited in spatial resolution by either the wavelength of the radiation used or by the aberrations of the optical elements. This is true whether one uses a scanning probe or a fixed beam method. The reason for the wavelength limit of resolution is due to the far field methods of producing or detecting the radiation. If one resorts to restricting our probes to the near field optical region, then the possibility exists of obtaining spatial resolutions more than an order of magnitude smaller than the optical wavelength of the radiation used. In this paper, we will describe the principles underlying such "near field" imaging and present some preliminary results from a near field scanning optical microscope (NS0M) that uses visible radiation and is capable of resolutions comparable to an SEM. The advantage of such a technique is the possibility of completely nondestructive imaging in air at spatial resolutions of about 50nm.

scholarly journals Recent advances in characterizing the “bee” structures and asphaltene particles in asphalt binders

2020 ◽  
Vol 13 (6) ◽  
pp. 697-706
Author(s):  
Yuhong Wang ◽  
Kecheng Zhao ◽  
Fangjin Li ◽  
Qi Gao ◽  
King Wai Chiu Lai
Keyword(s):  
Near Field ◽  
Asphalt Binder ◽  
Optical Microscope ◽  
Asphalt Binders ◽  
Zero Shear Viscosity ◽  
Surface Features ◽  
Asphaltene Content ◽  
Scanning Transmission ◽  
Before And After ◽  
Binder Aging

AbstractThe microscopic surface features of asphalt binders are extensively reported in existing literature, but relatively fewer studies are performed on the morphology of asphaltene microstructures and cross-examination between the surface features and asphaltenes. This paper reports the findings of investigating six types of asphalt binders at the nanoscale, assisted with atomic force microscopy (AFM) and scanning transmission electron microscopy (STEM). The surface features of the asphalt binders were examined by using AFM before and after being repetitively peeled by a tape. Variations in infrared (IR) absorbance at the wavenumber around 1700 cm−1, which corresponds to ketones, were examined by using an infrared s-SNOM instrument (scattering-type scanning near-field optical microscope). Thin films of asphalt binders were examined by using STEM, and separate asphaltene particles were cross-examined by using both STEM and AFM. In addition, connections between the microstructures and binder’s physicochemical properties were evaluated. The use of both microscopy techniques provide comprehensive and complementary information on the microscopic nature of asphalt binders. It was found that the dynamic viscosities of asphalt binders are predominantly determined by the zero shear viscosity of the corresponding maltenes and asphaltene content. Limited samples also suggest that the unique bee structures are likely related to the growth of asphaltene content during asphalt binder aging process, but more asphalt binders from different crude sources are needed to verify this finding.

Optical constants from scattering-type scanning near-field optical microscope

2021 ◽  
Vol 118 (4) ◽  
pp. 041103
Author(s):  
Xiao Guo ◽  
Karl Bertling ◽  
Aleksandar D. Rakić
Keyword(s):  
Optical Constants ◽  
Near Field ◽  
Optical Microscope

Observation of subcellular structures of neurons by an illumination mode near-field optical microscope under an optical feedback control

1996 ◽  
Vol 3 (6) ◽  
pp. A463-A467
Author(s):  
Rajagopalan Uma Maheswari ◽  
Shuji Mononobe ◽  
Hitoshi Tatsumi ◽  
Yoshifumi Katayama ◽  
Motoichi Ohtsu
Keyword(s):  
Feedback Control ◽  
Optical Feedback ◽  
Near Field ◽  
Optical Microscope ◽  
Illumination Mode
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