Optimization of microsphere optical lithography for nano-patterning

2021 ◽  
Author(s):  
Liliia N. Dvoretckaia ◽  
Alexey M Mozharov ◽  
Yury Berdnikov ◽  
Ivan Sergeevich Mukhin
Keyword(s):  
High Refractive Index ◽  
Exposure Dose ◽  
Si Substrate ◽  
Photoresist Layer ◽  
Realistic Modeling ◽  
Single Sphere ◽  
Simulation Results ◽  
Original Approach ◽  
System Geometry ◽  
Nano Patterning

Abstract We present an original approach to realistic modeling of light focusing by microsphere systems to form the photonic jets for nano-patterning of the substrates with high refractive index. In simulations we analyze the photonic jets produced by a single sphere and close-packed array of microspheres on the photoresist layer and Si substrate. We show how the lithographic profiles can be controlled by varying the exposure dose and system geometry in wide ranges of photoresist layer thicknesses and microsphere sizes. The modeling covers the entire lithographic system and accounts for the interference of focused light transmitted through the microlenses and reflected from the Si substrate. We use our approach to optimize the size of the lithographic pattern and confirm the simulation results experimentally. The suggested set of methods is rather universal and may be applied to other microlens and resist materials to minimize lithography lateral resolution.

The influence of single layer MoS2 flake on the propagated surface plasmons of silver nanowire

2021 ◽  
Author(s):  
Liu Lu ◽  
Tiantian Zhao ◽  
Lei Chen ◽  
Chenyang Wang ◽  
Zhiqiang Zhou ◽  
...  
Keyword(s):  
Refractive Index ◽  
Single Layer ◽  
High Refractive Index ◽  
Transmission Efficiency ◽  
Silver Nanowire ◽  
Propagation Loss ◽  
Optical Barrier ◽  
Propagation Length ◽  
Simulation Results ◽  
Ag Nanowire

Abstract We demonstrate the enhancement of both excitation and transmission efficiency of the propagated surface plasmon (SP) of Ag nanowire (Ag NW) in hybrid Ag-MoS2 structure by contrasting the SP propagation of the same Ag NW on different substrates including silicon substrate, monolayer MoS2, or partially overlapping the Ag NW on MoS2 flake. The simulation results indicate that with the assistance of MoS2, the leaky radiation of the hybrid plasmonic modes of the H1 and H2 can be prominently suppressed by the high refractive index dielectric layer of the MoS2, which provides an optical barrier blocking the leaky radiation, resulting in the reduced propagation loss. Our work provides a feasible and effective method to enhance the SP propagation length.

Optimization of a Novel Micro-Hotplate for Gas Sensor

2013 ◽  
Vol 423-426 ◽  
pp. 2317-2320
Author(s):  
Chang Chun Li ◽  
Xiao Bo Zhang ◽  
Li Liu
Keyword(s):  
Temperature Distribution ◽  
Gas Sensor ◽  
Uniform Temperature ◽  
Si Substrate ◽  
Uniform Temperature Distribution ◽  
Sensor Sensitivity ◽  
Electrode Space ◽  
Higher Temperature ◽  
Simulation Results ◽  
Novel Design

A novel design of micro-hotplate is proposed for micro-structural gas sensor. The simulation results of ANSYS reveal that higher temperature and more uniform temperature distribution was achieved in the micro-hotplate when the thickness of SiO2, thickness of Si substrate, electrode width and electrode space were designed to be 100, 200, 20 and 230 μm, respectively. The new micro-hotplate is benefit for the improvement of sensor sensitivity.

Formation of Counter Doped Shallow Junctions by Boron and Antimony Implantation and Codiffusion in Silicon

1997 ◽  
Vol 469 ◽  
Author(s):  
S. Solmi ◽  
R. Canteri
Keyword(s):  
Si Substrate ◽  
Junction Region ◽  
Simulation Code ◽  
Acceptor Interaction ◽  
Thermal Budget ◽  
Enhanced Diffusion ◽  
Shallow Junctions ◽  
Donor Acceptor ◽  
Simulation Results ◽  
Good Agreement

ABSTRACTVery shallow p+/n junctions (lower than 60 nm) have been fabricated by implanting Sb and subsequently BF2, at a higher dose, in a n-type Si substrate. The preamorphisation with Sb avoids the B channeling and increases the n-type doping in the junction region, thus confining the depth of the p layer. Furthermore, both the transient enhanced diffusion, being the B implanted in a preamorphized layer, and the standard diffusion, due to the pairing between donors and acceptors, are strongly reduced. This procedure allows us to obtain very shallow junctions even after annealings with relatively high thermal budget, like 800 C/8h, or 900 C/lh, or 950 C/15min or 1000 C/60s. Dopant diffusion is strongly affected by the direct donor-acceptor interaction. Good agreement between experimental and simulation results can only be obtained using a simulation code which takes into account the formation of neutral, near immobile, Sb-B pairs.

Dopant Diffusion in Silicon Substrate during Oxynitride Process

2000 ◽  
Vol 610 ◽  
Author(s):  
Nobutoshi Aoki ◽  
Toshitake Yaegashi ◽  
Yuji Takeuchi ◽  
Makoto Fujiwara ◽  
Naoki Kusunoki ◽  
...  
Keyword(s):  
Reasonable Agreement ◽  
Nitrogen Concentration ◽  
Surface Recombination ◽  
Anomalous Behavior ◽  
Dopant Diffusion ◽  
Si Substrate ◽  
Enhanced Diffusion ◽  
Surface Recombination Rate ◽  
Oxynitride Film ◽  
Simulation Results

AbstractWe found an anomalous behavior of dopant diffusion in Si substrate during the oxynitride process. SIMS measurements showed a notably enhanced diffusion during the NO and N2O oxynitride process. The considerably enhanced diffusion was also observed in re-oxidation of oxynitride film grown by the NO annealing or NH3 nitridation of a SiO2 film. In order to simulate the enhanced diffusion, an enhancement coefficient was introduced, showing that the simulation results are in reasonable agreement with the experimental ones. We applied the diffusion model to the simulations of MOSFETs fabricated under various conditions of the oxynitride process. The device characteristics of MOSFETs were successfully reproduced by adopting a suitable dependence of nitrogen concentration CN on the surface recombination rate of interstitial Si at the oxynitride/Si substrate interface.

A Novel Micro-Hotplate Designed for Micro-Gas Sensor

2013 ◽  
Vol 411-414 ◽  
pp. 1569-1572
Author(s):  
Ji Li ◽  
Xiao Bo Zhang ◽  
Li Liu
Keyword(s):  
Temperature Distribution ◽  
Gas Sensor ◽  
Uniform Temperature ◽  
Si Substrate ◽  
Original Design ◽  
Uniform Temperature Distribution ◽  
Micro Gas Sensor ◽  
Electrode Space ◽  
Higher Temperature ◽  
Simulation Results

A original design of micro-hotplate is proposed for micro-structural gas sensor. The simulation results of ANSYS reveal that higher temperature and more uniform temperature distribution was achieved in the micro-hotplate when the thickness of SiO2, thickness of Si substrate, electrode width and electrode space were designed to be 100, 200, 20 and 250 μm, respectively. The new micro-hotplate is beneficial to improving the sensor sensitivity.

Fabrication of SU-8 Microneedle Based on Backside Exposure Technology

2015 ◽  
Vol 645-646 ◽  
pp. 853-858 ◽  
Author(s):  
Li Qun Du ◽  
Zhong Zhou Wang ◽  
Xiao Peng Ruan ◽  
Sheng Li Chen ◽  
Qing Shan
Keyword(s):  
Light Intensity ◽  
Mass Production ◽  
Uv Light ◽  
Low Cost ◽  
Surface Profile ◽  
Optimization Method ◽  
Exposure Dose ◽  
Light Intensity Distribution ◽  
Microneedle Arrays ◽  
Simulation Results

An optimization method for fabricating 3D microneedle arrays with larger cone angles through backside exposure is demonstrated in this paper. A photo mask was designed to fabricate SU-8 microneedle based on diffraction of UV light. A circular hole diffraction was simulated with Matlab to obtain light intensity distribution. The simulation results show that the cone angles and surface profile can be adjusted by changing the thickness of substrate and exposure dose. Based on the simulation results, the microneedles with heights of 265 μm to 380 μm and cone angles in the range of 5.1° to 15.6° were fabricated by the backside exposure technology through one time UV lithography. Compared with previous approaches, the fabrication process in this paper takes advantages of simple, low cost and mass production.

Comparison of Turbulence Models for Single Sphere Simulation Study Under Supercritical Fluid Condition

2017 ◽  
Vol 12 (4) ◽  
Author(s):  
J. Malang ◽  
P. Kumar ◽  
A. Saptoro ◽  
M. O. Tade
Keyword(s):  
Carbon Dioxide ◽  
Flow Characteristics ◽  
Turbulence Models ◽  
Reynolds Numbers ◽  
Velocity Profiles ◽  
Near Wake ◽  
Supercritical Conditions ◽  
Flow Features ◽  
Single Sphere ◽  
Simulation Results

AbstractIn this paper, the comparison of turbulence models for fluid flow past single sphere under supercritical conditions is reported. Firstly, Dixon et al.’s models [1], which are under non-supercritical conditions, were used as benchmarks to validate the simulated results. Two turbulence models namely RNGk-εand SSTk-ωmodels parameters were fine-tuned accordingly in order to obtain almost comparable results generated by Dixon et al.’s models [1]. The simulation works were then extended to simulate flow of supercritical carbon dioxide. The second part of this paper, therefore, presents a comparative study of the turbulence models i. e. standardk-ε, RNGk-ε, realizablek-εand SSTk-ωmodels. This study emphasises on the predictions and evaluations of the velocity profiles at different flow regimes namely recirculation, recovery and near-wake. Simulations were carried out to determine the velocity profiles at subcritical and supercritical conditions by varying Reynolds numbers (2000 and 20,000), pressures (65 and 80 bar) and temperatures (283.15 and 308.15K). Simulation results indicate that the predicted results are consistent with the literature data. Interesting flow features were identified for all the simulations. The results of this study also reveal that the SSTk-ωturbulence model was able to better capture the flow characteristics near-wake of the sphere.

Facile solvothermal synthesis of high refractive index ZrO2 spheres: estimation of the enhanced light extraction efficiency

RSC Advances ◽  
2015 ◽  
Vol 5 (100) ◽  
pp. 81915-81919 ◽  
Author(s):  
Jin Young Park ◽  
G. Seeta Rama Raju ◽  
Byung Kee Moon ◽  
Jung Hyun Jeong
Keyword(s):  
Refractive Index ◽  
Solvothermal Synthesis ◽  
Extraction Efficiency ◽  
High Refractive Index ◽  
Light Extraction ◽  
Light Extraction Efficiency ◽  
Simulation Results

LightTools simulation results revealed that the light extraction efficiency of an LED has been improved to 70.12% when ZrO2 spheres were coated on the GaN surface.

Transmission Electron Microscopy studies of the vacancy ordering in YSI2-X thin films

1991 ◽  
Vol 49 ◽  
pp. 562-563
Author(s):  
F.-R. Chen ◽  
T. L. Lee ◽  
L. J. Chen
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Thin Films ◽  
Diffraction Pattern ◽  
Annealing Temperature ◽  
Lattice Mismatch ◽  
Si Substrate ◽  
Metal Thin Films ◽  
Transmission Electron ◽  
Vacancy Ordering

YSi2-x thin films were grown by depositing the yttrium metal thin films on (111)Si substrate followed by a rapid thermal annealing (RTA) at 450 to 1100°C. The x value of the YSi2-x films ranges from 0 to 0.3. The (0001) plane of the YSi2-x films have an ideal zero lattice mismatch relative to (111)Si surface lattice. The YSi2 has the hexagonal AlB2 crystal structure. The orientation relationship with Si was determined from the diffraction pattern shown in figure 1(a) to be and . The diffraction pattern in figure 1(a) was taken from a specimen annealed at 500°C for 15 second. As the annealing temperature was increased to 600°C, superlattice diffraction spots appear at position as seen in figure 1(b) which may be due to vacancy ordering in the YSi2-x films. The ordered vacancies in YSi2-x form a mesh in Si plane suggested by a LEED experiment.

Electron microscopy studies of PZT ferroelectric film capacitor structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1364-1365
Author(s):  
V. Kaushik ◽  
P. Maniar ◽  
J. Olowolafe ◽  
R. Jones ◽  
A. Campbell ◽  
...  
Keyword(s):  
Electric Fields ◽  
Sol Gel ◽  
Ferroelectric Material ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Lead Zirconium Titanate ◽  
Si Substrate ◽  
Film Capacitor ◽  
Pzt Films ◽  
High Dielectric

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.

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