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This article discusses the important role that optical lithography has played in realizing Moore's Law. With the introduction of Artificial Intelligence, Machine Learning, and the Internet of Things, the demand for computing power and data storage capacity has never been as large as today. Optical lithography has been able to keep up with the resolution demand by increasing the Numerical Aperture of the projection Lens, decreasing the wavelength and innovative resist schemes. After the introduction of Immersion lithography and Double patterning, EUV was introduced by the industry. Although the transition from 193 nm lithography to EUV lithography was very difficult, EUV follows the same scaling laws as Optical Lithography. The conclusion is that the scaling laws of Optical Lithography continue to support Moore's Law, through the development of high NA EUV Lithography.

The energy deposited in resist during its exposure by ion beam was simulated for ions from a set of rare gases and for gallium. It was shown that the distribution of energy density can be approximated by the product of two Gaussian functions. One of them describes the lateral distribution of energy, the second the dependence on depth. The widths and centres of these Gaussian functions are determined by the energy length (also mentioned in the literature as "Range" or "mean length of trajectories"), the mass of ions and the average atomic number of resist. The obtained description would make it possible to estimate the size of the resist modified volume for any type of ion with energy of tens kiloelectronvolts. So it can be used for a priori estimates of resolution and performance, as well as for the choice of beam energy and ion type based on this. [ABSTRACT FROM AUTHOR]

Direct printing of spin-on functional films is probably the most efficient method to develop low-cost novel photonic nanodevices, such as diffraction gratings, planar waveguides, nano- lasers, and antireflective coatings. For these applications high refractive index transparent materials are demanded; however, this class of materials generally requires inorganic oxides, well known for their hardness, typical of ceramic materials, and so incompatible with a soft character of printable resins. Herein, inorganic high refractive index TiO2 micro- and nano- structures, with unusual depth up to 600 nm and aspect ratio larger than 5, are obtained by combining thermal nanoimprint lithography (NIL) with UV curing. To achieve printed patterns, a hybrid organic-inorganic spin-on film is deposited at low-temperature by sol–gel processing. Two distinct bottom-up synthetic approaches are used, called in situ and ex situ, using titanium isopropoxide (90%) or TiO2 anatase nanoparticles (70%), respectively, and adding a silica sol modified by organic moieties. The two syntheses were optimized to obtain, after patterning by thermal imprint, amorphous or crystalline titania crack-free micro- and nano- patterns for in situ and ex situ, respectively. The further UV irradiation converts imprinted films to totally inorganic patterns, through the titania photocatalytic effect, allowing refractive indexes up to 1.82 at 632 nm to be achieved. This novel strategy of combining thermal imprint with UV exposure allows inorganic deep patterns to be fabricated without a calcination step, which is generally needed for inorganic resists processing. Eventually, a thermal treatment only at 300 °C can be applied to achieve a final refractive index of 2 at 632 nm. Highlights: A simple straightforward one-step surface patterning process by NIL technology of high refractive index TiO2 systems is proposed. The hybrid nature of films combines the required intrinsic properties of inorganic titania and the simple processing of organic resists. Micro- and nano-inorganic structures up to 600 nm deep and refractive index up to 2 at 632 nm are achieved. [ABSTRACT FROM AUTHOR]

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Patterning photoresist with extreme control over dose and placement is the first crucial step in semiconductor manufacturing. However, how can the activation of modern complex resist components be accurately measured at sufficient spatial resolution? No exposed nanometre-scale resist pattern is sufficiently sturdy to unalteredly withstand inspection by intense photon or electron beams, not even after processing and development.This paper presents experimental proof that infrared atomic force microscopy (IR-AFM) is sufficiently sensitive and gentle to chemically record vulnerable yet valuable lithographic patterns in a chemically amplified resist after exposure prior to development. Accordingly, IR-AFM metrology provides long-sought insights into changes in the chemical and spatial distribution per component in a latent resist image, both directly after exposure and during processing. With these to-be-gained understandings, a disruptive acceleration of resist design and processing is expected.

A binary Te‐free phase‐change material Ge9.15Sb90.85 (GS) is investigated as the heat‐mode resist. A high etching selectivity ratio can be achieved by matching a suitable developer. A reasonable explanation for the positive development is proposed based on the chemical binding energy analysis. High‐resolution relief patterns are fabricated on the GS films by laser direct writing and wet etching. It reveals that GS is a promising heat‐mode resist for the fabrication of photonic devices. [ABSTRACT FROM AUTHOR]

Efficient and accurate developer screening is critical for high-resolution lithography. In this study, a multiparameter (MP) method simultaneously based on the Hansen solubility parameters (HSP), two-component solubility parameters (TSP), and order parameter (OP) is proposed for the developer screening of molecular glass resists via molecular dynamics simulation. A customized solvent database, including 80 organic solvents, is created for the subsequent developer screening. Two diagram forms of HSP ( δ D - δ P - δ H diagram and δ diagram is utilized due to its higher solubility prediction consistency with OP. Then, two solubility prediction diagrams, i.e., HSP&OP and TSP&OP diagrams, were formed using the MP method. The developer screening scheme using the MP method is illustrated for a decomposable resist, AD10BOC, and a cross-linkable resist, AD4C. Meanwhile, the feasibility of the developer screening scheme is verified by practical lithography experiments. In addition, relative solvation free energy (RSFE) calculations and dissolution experiments of six resists are implemented to further confirm the accuracy of OP in reflecting the relative solubility of the resist in various solvents. This study presents a viable approach for developer screening, which will facilitate the development of resist materials. V - δ H diagram) were investigated, and the δ V - δ H diagram is utilized due to its higher solubility prediction consistency with OP. Then, two solubility prediction diagrams, i.e., HSP&OP and TSP&OP diagrams, were formed using the MP method. The developer screening scheme using the MP method is illustrated for a decomposable resist, AD10BOC, and a cross-linkable resist, AD4C. Meanwhile, the feasibility of the developer screening scheme is verified by practical lithography experiments. In addition, relative solvation free energy (RSFE) calculations and dissolution experiments of six resists are implemented to further confirm the accuracy of OP in reflecting the relative solubility of the resist in various solvents. This study presents a viable approach for developer screening, which will facilitate the development of resist materials.

In this era, electronic devices such as mobile phones, computers, laptops, sensors, and many more have become a necessity in healthcare, for a pleasant lifestyle, and for carrying out tasks quickly and easily. Different types of temperature sensors, biosensors, photosensors, etc., have been developed to meet the necessities of people. All these devices have chips inside them fabricated using diodes, transistors, logic gates, and ICs. The patterning of the substrate which is used for the further development of these devices is done with the help of a technique known as lithography. In the present work, we have carried out a review on different types of lithographic techniques such as optical lithography, extreme ultraviolet lithography, electron beam lithography, X-ray lithography, and ion beam lithography. The evolution of these techniques with time and their application in device fabrication are discussed. The different exposure tools developed in the past decade to enhance the resolution of these devices are also discussed. Chemically amplified and non-chemically amplified resists with their bonding and thickness are discussed. Mask and maskless lithography techniques are discussed along with their merits and demerits. Device fabrication at micro and nano scale has been discussed. Advancements that can be made to improve the performance of these techniques are also suggested. [ABSTRACT FROM AUTHOR]

One of the ways to use a focused ion beam in lithographic processes to create nanostructures is through the exposure of special sensitive materials, i.e., resists. As a result of exposure, the solubility of such a material increases ("positive" resist) or, conversely, decreases ("negative" resist). Subsequent selective irradiation and development of the resist make it possible to create a predetermined pattern on the substrate. This work is aimed at developing the theoretical foundations for this ion lithography method. A practically important case of stopping heavy ions in an organic resist, the average atomic mass of which is much less than the mass of the incident ion, is considered. Expressions for the "energy" and transport lengths of ions are obtained. The calculations are carried out assuming a power-law interaction potential. The "energy" length characterizes the depth of penetration of ions into the material, and the transport length is related to beam expansion due to scattering. Therefore, these lengths are the main characteristics of the zone in which the ion-beam energy is absorbed. [ABSTRACT FROM AUTHOR]

The paper gives a synthetic description of the lithography processes used to define geometric configurations in the technology of structures with thin films for MEMS applications. There are presented, also, performances of these technological procedures, some results of the work' authors and progress trends in this field. [ABSTRACT FROM AUTHOR]

Treating multiple lung lesions synchronously using a single-isocenter volumetric modulated arc therapy (VMAT) stereotactic body radiation therapy (SBRT) plan can improve treatment efficiency and patient compliance. However, due to set up uncertainty, aligning multiple lung tumors on a single daily cone beam CT (CBCT) image has shown clinically unacceptable loss of target(s) coverage. Herein, we propose a Restricted Single-Isocenter Stereotactic Body Radiotherapy (RESIST), an alternative treatment that mitigates patient setup uncertainties. Twenty-one patients with two lung lesions were treated with single-isocenter VMAT-SBRT using a 6MV-FFF beam to 54 Gy in 3 fractions (n = 7) or 50 Gy in 5 fractions (n = 14) prescribed to 70-80% isodose line. To minimize setup uncertainties, each plan was re-planned using the RESIST method, utilizing a single-isocenter placed at the patient's mediastinum. It allows for an individual plan to be created for each tumor, using the first plan as the base-dose for the second plan, while still allowing both tumors to be treated in the same session. The technique uses novel features in Eclipse, including dynamic conformal arc (DCA)-based dose and aperture shape controller before each VMAT optimization. RESIST plans provided better target dose conformity (p < 0.001) and gradient indices (p < 0.001) and lower dose to adjacent critical organs. Using RESIST to treat synchronous lung lesions with VMAT-SBRT significantly reduces plan complexity as demonstrated by smaller beam modulation factors (p < 0.001), without unreasonably increasing treatment time. RESIST reduces the chance of a geometric miss due by allowing CBCT matching of one tumor at a time. Placement of isocenter at the mediastinum avoids potential patient/gantry collisions, provides greater flexibility of noncoplanar arcs and eliminates the need for multiple couch movements during CBCT imaging. Efficacy of RESIST has been demonstrated for two lesions and can potentially be used for more lesions. Clinical implementation of this technique is ongoing. [ABSTRACT FROM AUTHOR]

Synchronous treatment of two lung lesions using a single‐isocenter volumetric modulated arc therapy (VMAT) stereotactic body radiation therapy (SBRT) plan can decrease treatment time and reduce the impact of intrafraction motion. However, alignment of both lesions on a single cone beam CT (CBCT) can prove difficult and may lead to setup errors and unacceptable target coverage loss. A Restricted Single‐Isocenter Stereotactic Body Radiotherapy (RESIST) method was created to minimize setup uncertainties and provide treatment delivery flexibility. RESIST utilizes a single‐isocenter placed at patient's midline and allows both lesions to be planned separately but treated in the same session. Herein is described a process of automation of this novel RESIST method. Automation of RESIST significantly reduced treatment planning time while maintaining the benefits of RESIST. To demonstrate feasibility, ten patients with two lung lesions previously treated with a single‐isocenter clinical VMAT plan were replanned manually with RESIST (m‐RESIST) and with automated RESIST (a‐RESIST). a‐RESIST method automatically sets isocenter, creates beam geometry, chooses appropriate dose calculation algorithms, and performs VMAT optimization using an in‐house trained knowledge‐based planning model for lung SBRT. Both m‐RESIST and a‐RESIST showed lower dose to normal tissues compared to manually planned clinical VMAT although a‐RESIST provided slightly inferior, but still clinically acceptable, dose conformity and gradient indices. However, a‐RESIST significantly reduced the treatment planning time to less than 20 min and provided a higher dose to the lung tumors. The a‐RESIST method provides guidance for inexperienced planners by standardizing beam geometry and plan optimization using DVH estimates. It produces clinically acceptable two lesions VMAT lung SBRT plans efficiently. We have further validated a‐RESIST on phantom measurement and independent pretreatment dose verification of another four selected 2‐lesions lung SBRT patients and implemented clinically. Further development of a‐RESIST for more than two lung lesions and refining this approach for extracranial oligometastastic abdominal/pelvic SBRT, including development of automated simulated collision detection algorithm, merits future investigation. [ABSTRACT FROM AUTHOR]

Police use of force is one of the most critical issues in policing with research consistently finding that the best predictor of force is suspect resistance. Yet, resistance itself is relatively rarely researched. This study drew from the Drug Use Monitoring in Australian (DUMA) program – Australia's longest running cross-sectional survey of offenders. Data was analyzed using multivariate and multi-level logistic regression to identify factors that predict suspect resistance in terms of whether the suspect was charged with resisting arrest or not. Results showed that while suspect resistance was relatively rare, it was more common under specific situations. Factors relating to offender demographics, crime, temporal/situational, and policing district all contributed to whether suspects were charged with resisting arrest. Moreover, the results showed that the policing region was the strongest predictor of whether a detainee was charged with suspect resistance. These findings highlight the complex and multifaceted nature of police-citizen encounters. [ABSTRACT FROM AUTHOR]

In this era, electronic devices such as mobile phones, computers, laptops, sensors, and many more have become a necessity in healthcare, for a pleasant lifestyle, and for carrying out tasks quickly and easily. Different types of temperature sensors, biosensors, photosensors, etc., have been developed to meet the necessities of people. All these devices have chips inside them fabricated using diodes, transistors, logic gates, and ICs. The patterning of the substrate which is used for the further development of these devices is done with the help of a technique known as lithography. In the present work, we have carried out a review on different types of lithographic techniques such as optical lithography, extreme ultraviolet lithography, electron beam lithography, X-ray lithography, and ion beam lithography. The evolution of these techniques with time and their application in device fabrication are discussed. The different exposure tools developed in the past decade to enhance the resolution of these devices are also discussed. Chemically amplified and non-chemically amplified resists with their bonding and thickness are discussed. Mask and maskless lithography techniques are discussed along with their merits and demerits. Device fabrication at micro and nano scale has been discussed. Advancements that can be made to improve the performance of these techniques are also suggested.

Soil erosion on sloping farmland has posed a great challenge on land productivity and crop yield, resulting coarse soil and less arable area due to the losing of fine soil particles. Moreover, N and P in soil that migrated with runoff and sediment can also affect the quality of downstream water. Therefore, it is highly demanding to control soil erosion on sloping farmland. Currently, various measures are being taken in the long run, covering from biological, tillage, and engineering. Soil amendments can be used to greatly reduce soil erosion and increase cohesion between surface soil particles, which can maintain surface soil structure to prevent soil crust, resulting the increase in soil infiltration rate, while the decrease in the surface runoff. Therefore, a new material related to soil amendments has drawn much attention. In recent years, the Changjiang River Sciences Research Institute has developed a new seaweed polysaccharide Anti-erosion Material SA-01. This study aims to explore the effect of SA-01 concentration on runoff and sediment yield of red soil, in order to verify the new polysaccharide corrosion inhibitor (SA-01) from the seaweed in controlling soil and water loss on a slope. Taking the typical red soil in southern China as an example, a series of artificial rainfall experiments were carried out, where the rainfall intensity of 90 mm/h, and the slope of 5°, 10°, and 15° under various concentrations of 0, 0.25%, 0.50%, 0.75%, and 1.00%. The mechanism of SA-01 on soil erosion was analyzed in a combination of soil water repellency and aggregate stability experiments. The results show that under the same slope, the runoff yield on the slope with SA-01 was higher than that on the control slope. The runoff yield on the slope decreased first and then increased, while the cumulative runoff on the slope decreased first and then increased with the increase of applied concentration. The increment ratio of surface flow increased as the SA-01 concentration increased, indicating that SA-01 can significantly reduce sediment yield on a slope. In the initial runoff yield stage, SA-01 can significantly reduce the slope sediment yield. In the stage of surface erosion, the slope without SA-01 reached the maximum, then fell rapidly, and eventually became stable. Compared with the control slope, the sediment yield of SA-01 slope fluctuated slightly in the early stage of runoff yield, and the time to reach stable sediment yield was earlier than that of the control slope. With the increase of applied concentration, the sediment yield decreased significantly. SA-01 can significantly increase the runoff while reduce the sediment yield of different slopes, due mainly to the change of soil hydrophilic to water repellency, and the decrease of infiltration rate. Soil water repellency was improved after SA-01 was applied. When the concentration was 0.25%, the sample retained the same hydrophilicity as the original soil. When the concentration was more than 0.25%, the soil began to change from hydrophilicity to repulsion. Due to the soil Ca2+ cation chelation with SA-01, the soil particles generated on the surface of a layer with a certain intensity. The presence of preservation layer increased soil water repellency, while reduced the soil aggregate dispersion, and thereby to improve the stability of soil aggregates at different levels. SA-01 can provide a new idea for soil and water conservation of red soil on a slope. [ABSTRACT FROM AUTHOR]

The feature of the promising tool of lithographic nanostructuring based on selective exposure of polymer resist by ion beam is very compact (of about tens of nanometers) beam interaction volume. Herewith the main part of beam energy is deposited in the resist and is spent to its modification. It causes the set of advantages specific for this method: sub-10 nanometer resolution achievable, very high energy efficiency and almost complete absence of proximity effect. But also due to this feature absorbed doze essentially inhomogeneous in resist and the dissolution rate is strongly dependent on depth. So the common procedure of resist contrast determination cannot be applied anymore. In the present work a new method for resist contrast determination considering the relation between dissolution rate and deposited energy density is suggested and realized. By using it for PMMA resist irradiated by 30 keV Ga+ ion beam the value of contrast was determined to be 3.1 and ions energy length was estimated to be 42 nm. [ABSTRACT FROM AUTHOR]

Chemical etching is a micro-machining manufacturing process to produce micron-size components by applying of a chemical etching solution to remove unwanted part in the work-piece material. In this study aluminium was etched by different chemical agents (acid and base solution). The effects of selected chemical etching agents on depth of etch as well as the etch rate was investigated for aluminium. [ABSTRACT FROM AUTHOR]

Abstract For ultraviolet nanoimprint lithography (UV-NIL), the resist volume shrinkage during curing not only influences the pattern fidelity but also induces defects in the demolding process due to strong adhesion. To address this issue, a novel nanoimprint resist was formulated and characterized in this work. The new resist formulation contains 3,9-diethyl- 3,9-bis(allyloxymethyl)-1,5,7,11- tetraoxastetraoxaspiro [ 5 ] undecane (DB-TOSU), which is a liquid spiroorthocarbonate monomer that undergoes volume expansion upon acid-catalyzed polymerization. By mixing DB-TOSU with conventional volume-shrinking epoxy monomers at various weight ratios, the formulated resists had much reduced or even zero volume shrinkage. The resist volume shrinkage, elastic modulus, and demolding force decreased with increasing DB-TOSU weight ratio in resist formulation. When DB-TOSU reached 50 wt%, the demolding force was reduced by 69% with an adequate elastic modulus (75 MPa) and low shrinkage (1.86%). This novel resist formulation has the potential to allow high-fidelity pattern replication and reduce demolding defects in UV-NIL. Graphical abstract Unlabelled Image Highlights • The liquid volume-expanding monomer DB-TOSU was successfully synthesized. • New UV nanoimprint resists were formulated with low volume shrinkage. • The new resists significantly reduce demolding forces in nanoimprint. [ABSTRACT FROM AUTHOR]

Gbongudu community, Ibadan underlain by crystalline rocks of Basement Complex of Southwestern Nigeria has need for alternative water supply due to inadequacies of surface water supply and common occurrences of low yield or dry boreholes coupled with rapid development within the community. Geophysical investigation involving electrical resistivity was carried out with the aim of evaluating the groundwater potential of the community. Thirty-three (33) Vertical Electrical Soundings were acquired across the community adopting Schlumberger electrode configuration with current electrode separation (AB) varying from 2 to 200 m. The acquired field data were interpreted using partial curve matching with suitable auxiliary chart and "RESIST" resistivity sounding interpretation software was also used for iteration. The results revealed two to five geo-electric layers, namely, topsoil, clayey soil, lateritic clay, weathered layer, fractured unit and fresh basement. The weathered and the fractured units form the aquiferous zones in the area investigated. Thematic maps of geoelectric and Dar-Zarrouk parameters produced from the interpreted VES data are aquifer unit (weathered layer) thickness map, aquifer unit (weathered layer) resistivity map, overburden thickness map, basement resistivity map, basement topography map, reflection coefficient map, total longitudinal conductance map, total transverse resistance map and electrical anisotropy (coefficient of anisotropy) map. The thematic maps were combined to form a single component which gives the groundwater potential map of the study area. The groundwater potential map was used to classify the study area into poor, low and good aquifer potential zones. The study reveals that the weathered and fractured zone that occur in the southeastern part of the study area constitute the water bearing zone which can be regarded as good groundwater potential. This study has provided evidence on the hydrogeologic framework and subsurface nature of main aquifer units in the area. [ABSTRACT FROM AUTHOR]