Immersion Technology Research Articles

Применение магнетронных устройств в комплексной плазменно-иммерсионной технологии обработки поверхности

Применение магнетронных устройств в комплексной плазменно-иммерсионной технологии обработки поверхности

Efficient Audio Rendering Using Angular Region-Wise Source Enhancement for 360$^{\circ }$ Video

In virtual reality, 360 $^{\circ }$ video services provided through head-mounted displays or smartphones are widely available. Among these, some state-of-the-art devices are able to render varying auditory location of an object perceived by the user when the visual location of the object in the video moves along with the change of the user's looking direction. Nevertheless, an acoustic immersion technology that generates binaural sound to maintain a good match between the auditory and visual localization of an object in 360 $^{\circ }$ video has not been studied sufficiently. This study focuses on an approach that synthesizes semibinaural sound being composed of virtual sources located in each angular region and the representative head related transfer functions of each angular region. To minimize the calculation cost on audio rendering and to reduce latency in downloading data from servers, the number of angular regions should be reduced while maintaining a good match between the auditory and visual localization of an object. In this paper, we investigate the minimum number of angular regions at which it is possible to maintain a good match by conducting subjective tests using a 360 $^{\circ }$ video viewing system composed of virtual images and sound sources. From the subjective tests, it was confirmed that the acoustic field should be divided into more than six equispaced angular regions so as to achieve natural auditory localization that matches an object's location in 360 $^{\circ }$ video.

A new type of sulfonium salt copolymers generating polymeric photoacid: Preparation, properties and application

Photoacid generators (PAGs) are critical components in chemically amplified (CA) photoresists system, among which small molecular sulfonium salts are commonly used but possess inherent incompatibility with polymer matrixes and acid migration during the post exposure baking (PEB) processes. PAG-bound polymers would be better choices for CA photoresists to acquire excellent lithographic performance. In this work, a new and convenient way is designed to prepare polymeric PAGs which generate polymeric photoacids and with this method the existing small molecular sulfonium salts can be transformed into polymeric compounds with convenience. Poly (sodium p-styrenesulfonate-co-tertiary-butyl methacrylate) (p(SSNa-co-t-BMA)) was prepared through free radical polymerization and then was further reacted with various sulfonium halides to give sulfonium salt copolymers. Different molecular weights of the copolymers can be obtained from Mn 5.5 × 103–2.5 × 104 with distribution coefficient between 1.18‐1.88. The ionic copolymers display good solubilities in common resist solvents. The thermal decomposition temperatures (Td) are around 150–155 °C and the glass transition temperatures (Tg) are above 130 °C. After exposed to light, the copolymers can generate polymeric photoacids. The photoacid generation efficiencies are determined around 0.31–0.34. UV spectra show big difference between the polymeric PAGs and the mixture of the corresponding small molecular sulfonium salts and framework polymers and demonstrate much better transparency of polymeric PAGs. Thick film 248-nm CA photoresist can be formed by one of the polymeric PAGs and partly protected poly(4-hydroxystyrene-co- tertiary-butyl methacrylate) (p(4-HS-co-t-BMA)), and display excellent performance with high height/width (H/W) ratio of 5:1 and resolution of 0.35 μm. These polymeric PAGs also have potentiality to be used in CA photoresists for other photolithography technologies such as 193-nm immersion technology.

Immersed multilayer biodegradable ureteral stent with reformed biodegradation: An in vitro experiment.

Objective The aim of this study was to develop a novel immersed multilayer biodegradable ureteral stent with reformed biodegradation and evaluate it in vitro. Methods Poly(glycolic-co-lactic acid) (PGLA), microsphere zein and BaSO4 were employed to produce a multilayer biodegradable stent using immersion technology. Tests of the biodegradable stents and conventional control stents were conducted in human urine in vitro to evaluate the biodegradable properties. The biocompatibility was assessed by the morphology and proliferation of urine-derived cells cultured with extracted media from the biodegradable stent and a latex material positive control. Results An immersed multilayer biodegradable stent was successfully produced. It began to degrade in week 2 and was fully degraded by week 4. The mass loss ratio in the first 2 weeks was low (approximately 10.0% at 1 week, 20.0% at 2 weeks) and increased after 3 weeks (approximately 70%) to the end of testing. During the first 2 weeks, the radial compression load performances of the biodegradable stents were better than those of the control stents with statistically significant differences ( p = 0.00, p = 0.01) and the tensile strengths were lower in the biodegradable stents than those in the control stents throughout the experiment. SEM showed that the stents degraded layer by layer from the outer to the inner wall. The influences on the cells of extracted medium from the biodegradable stents were morphologically slight and lower than 10% in relative growth rates. Conclusions This preliminary study demonstrates that the immersed multilayer biodegradable ureteral stent has good radial compression and biocompatible performance and can be degraded in vitro within 4 weeks in a moderate manner.

Extreme ultraviolet resist materials for sub-7 nm patterning.

Continuous ongoing development of dense integrated circuits requires significant advancements in nanoscale patterning technology. As a key process in semiconductor high volume manufacturing (HVM), high resolution lithography is crucial in keeping with Moore's law. Currently, lithography technology for the sub-7 nm node and beyond has been actively investigated approaching atomic level patterning. EUV technology is now considered to be a potential alternative to HVM for replacing in some cases ArF immersion technology combined with multi-patterning. Development of innovative resist materials will be required to improve advanced fabrication strategies. In this article, advancements in novel resist materials are reviewed to identify design criteria for establishment of a next generation resist platform. Development strategies and the challenges in next generation resist materials are summarized and discussed.

Surgical Simulation Update for Resident Education in Plastic Surgery

Simulation is defined as replication of a real-world process or system over time. Surgical Simulations have gained popularity in the recent years. There have been many studies evaluating the role of computer and real-life simulations in surgical training. In several surgical specialties, the use of standardized simulators has become a mandatory portion of the resident’s training, such as the fundamentals of laparoscopic surgery, which is a required part of the residency in general surgery.1 Simulators employ various types of models to represent real-world objects and systems. Some of the most common types of models in simulations include the following: Physical models: these types of models are physical objects representing a process or system in a controlled and simplified fashion. The systems used for training in fundamentals of laparoscopic surgery represent physical models of the abdomen. Mathematical models: these models provide a description of an object or a system using mathematical algorithms and concepts commonly within a computer simulation. Graphical models: these types of models are based on graphical depiction of an object or a system. Graphical models can be 2-dimensional or 3-dimensional. Finite element models: in this method of modeling, large and complex objects or systems are divided into much smaller and simpler parts with more predictable and defined behavior. The simulators can sum up the behavior of the smaller parts to replicate the larger and more complex objects. With advances in computer technology, the development of models has become easier and more affordable. A readily accessible source of data for creation of anatomical models is the Visible Human Project (https://www.nlm.nih.gov/research/visible/visible_human.html). The members of the American Council of Academic Plastic Surgeons Committee on Simulation in collaboration with a commercial animation company developed a computer-based simulator to teach the latissimus dorsi breast reconstruction technique to the residents and medical students.2 There are numerous other examples of simulators, both physical and computer based, which have been developed in the recent years by interested faculty and residents. An example is a project from the Case Medical Center in Cleveland, Ohio, which was spearheaded by one of the residents. With the help of a small institutional grant, a mobile application was developed to help improve the informed consent process by enabling the patient to visually navigate through a procedure.3 Touch Surgery is a London- and NYC-based company that has developed many simulations of surgical procedures based on real surgical videos. These simulations are accessible on smart phones and tablets (https://www.touchsurgery.com). With the advent of immersion technology, such as Oculus Rift (https://www.oculus.com/en-us/rift/) and Microsoft Hololens (https://www.microsoft.com/microsoft-hololens/en-us), the simulation world is experiencing a rapid shift toward virtual and augmented reality. Augmented reality represents a combination of computer-generated simulation and information superimposed on the real-world objects. The potential applications of these new technologies for medical and surgical training are immense. Surgical simulations have improved significantly in the recent years. Required technology has become more readily available. More surgeon educators should become involved in the development of simulators for training of the next generation of plastic surgeons.

Immersion and Invariance Based Robust Adaptive Control of High‐Speed Train with Guaranteed Prescribed Performance Bounds

AbstractThis paper proposes a novel robust adaptive algorithm for train tracking control with guaranteed prescribed transient and steady‐state performance. As speed increases, the inherent time‐varying uncertainties and unmodeled dynamics in the longitudinal dynamics of a high‐speed train seriously impacts the tracking performance of automatic train operation. To improve train operation performance, an estimator based on immersion and invariance technology is developed to recover the unknown and time‐varying plant parameters, and it renders the estimation error converging to a bounded residual set exponentially while providing more freedom for the controller. After certain error transformation, the prescribed tracking performance is introduced into the controller design. Then, an input‐to‐stable stable controller is developed through the backstepping technique, and it is proven that stabilization of the transformed system is sufficient to guarantee the prescribed performance. Rigorous theoretical analysis for the presented algorithm is provided, and a series of simulation studies also are given to verify the effectiveness of it.

Nonlinear adaptive trajectory tracking control for a quad-rotor with parametric uncertainty

A novel adaptive control algorithm to trajectory tracking control problem for a quad-rotor with uncertain mass and inertial parameters is presented based on the noncertainty equivalence principle. The estimation laws for quad-rotor mass and inertial parameters are developed with the introduction of stable attracting manifolds into the position-loop and attitude-loop adaptation process, respectively. The position and attitude trajectory tracking control algorithms are constructed through a unified immersion and invariance adaptive control technology. With extracting the desired attitude trajectory from the position-loop, the desired attitude trajectory for the attitude-loop is calculated from a command filter. The ultimately uniformly boundedness of the closed-loop system signals is derived for the quad-rotor under the proposed control algorithm. Simulation results demonstrate the performance of the proposed approach.

Temporary immersion systems in plant biotechnology

Plant tissue and organ cultures in vitro usually face technological challenges. When submerged cultivation of plant cells in a controlled environment is desired, the characteristic growth morphology and physiology of differentiated organ cultures present a problem in process scale‐up. Temporary immersion systems (TIS) were developed several decades ago. These systems are providing the most natural environment for in vitro culture of plant shoots and seedlings. Over the past few years, TIS have been recognized as a perspective technology for plant micropropagation, production of plant‐derived secondary metabolites, expression of foreign proteins, and potential solutions in phytoremediation. Nowadays, several TIS, operating on similar or divergent technological principles, have been developed and successfully applied in the cultivation of various plant in vitro systems, including somatic embryos and transformed root cultures. In this article, the operational principle and technological design of the most popular TIS are reviewed. In addition, recent examples of the application of temporary immersion technology for in vitro cultivation of plant tissue and organ cultures at laboratory and pilot scales are discussed. Finally, future prospects and challenges to the industrial realization of that fast‐developing technique are outlined.

Changing Technology Requirements of Mask Metrology in Semiconductor Industry

Upcoming Semiconductor Technology Nodes will still be based on optical lithography by ArF water immersion technology because there are still too many open issues preventing extreme ultraviolet (EUV) lithography from being introduced into production. Several kinds of multi- patterning technology are in use to overcome the optical resolution limitation of 193nm high NA illumination and still to achieve <32nm half-pitch. Mask registration metrology must be adapted to provide useful and comprehensive data on the mask contribution to wafer overlay

Bioactive tantalum metal prepared by micro-arc oxidation and NaOH treatment

The study aim was to evaluate the effect of micro-arc oxidation (MAO) and alkali treatment on porous tantalum specimens by foam immersion technology. Tantalum specimens modified by MAO formed an apatite layer on their surfaces in simulated body fluid (SBF). However, the leach liquor of these specimens shows toxicity to 3T3-E1 cells. When they were previously soaked in a 0.5 M NaOH aqueous solution at 60 °C for 24 h, there was no statistical difference between the leach liquor of specimens with NaOH pretreatment and the control in cell proliferation experiments. NaOH-treated tantalum metal can form more apatite on its surface in SBF than the control and specimens produced by MAO. Furthermore, a sodium tantalate hydrogel layer was observed on the specimen's surface by X-ray diffraction. Well defined actin stress fibers and bone-like tissue are distributed throughout the body of 3T3-E1 cells cultured on specimens after 5 days. Animal tests showed new bone formation in the gap between the specimens and the host bone after 4 weeks. Neovascularization and new bone ingrowth occurred within the pores of the specimens after 4 and 12 weeks, respectively. Our results indicated that highly bioactive tantalum metal can be obtained by simple chemical treatment.

Temporary immersion systems for Amaryllidaceae alkaloids biosynthesis by Pancratium maritimum L. shoot culture

The alkaloid patterns of sea daffodil (Pancratium maritimum L.) shoot culture, cultivated in a temporary immersion cultivation system were investigated. The shoots accumulated maximal amounts of biomass (0.8 g dry biomass/L and Growth Index = 1.6) at immersion frequency with 15 min flooding and 12 h stand-by periods. At this regime P. maritimum shoots achieved the highest degree of utilization of carbon source. Twenty-two alkaloids, belonging to narciclasine, galanthamine, haemanthamine, lycorine, montanine, tazettine, homolycorine and tyramine types were identified in intracellular and extracellular alkaloid extracts. The immersion frequency affected strongly the capacity of alkaloid biosynthesis in P. maritimum shoots and at the optimum conditions of cultivation, the total intracellular alkaloid content reached up to 3,469 μg/g dry biomass. The main biosynthesized alkaloids were haemanthamine (900.1 μg/g) and lycorine (799.9 μg/g). The obtained results proved that temporary immersion technology, as a cultivation approach, and P. maritimum shoots, as a biological system, are prospective for producing wide range bioactive alkaloids.

Transformation of Enhanced Glow Discharge Dynamics in Nitrogen Plasma Immersion Ion Implantation

In nitrogen enhanced glow discharge plasma immersion ion implantation, the implantation current increases sharply with the gas pressure when a threshold pressure is exceeded, indicating that the glow discharge dynamics changes with increasing diatomic gas flow rate. The voltage drop rendered by the anode glow produces noticeable N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> dissociation and electron-atom ionization in the positive column which expands to the cathode. As a result, charged particles reach the cathode more easily, and the larger plasma density and N <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> /N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> ratio in the positive column lead to the higher current. Our results clarify the implantation current characteristics and expedite adoption of this alternative plasma immersion technology.

Application of Water Immersion Ultrasonic Phased Array Technology in Wheel Rim Inspection

Rim is an important part of the wheels. It is often over loaded and has a complicated stress in use. Specially, at high speed circumstances, the quality of the work piece is closely connected. This paper combines the water immersion technology with the ultrasonic phased array technology to wheel detection. It introduces the basic principle, current situation at home and abroad of the water immersion ultrasonic phased array technology, and the comparison with the contacted ultrasonic phased array detection technology. According to the feature of the rim flaws, the methods to detect rim flaws with water immersion ultrasonic phased array technology are analyzed and tested. This system can finish the whole scanning in one time, improve the work efficiency and satisfy the testing requirements.

Simulation and Experimental Study on Multilayer Double-Patterning Processes

The imaging constraints imposed by the optics of current lithographic tools now require double-patterning (DP) processes. As lithography pushes past 32-nm resolution, the need to optimize material stacks, including resist, bottom anti-reflective coating (BARC), and substrate has never been greater for IC manufacturers. With thinner resists, DP, dual BARCs, and tri- and quad-layer schemes in the 193-nm immersion technology, the potential combinations are almost endless. Many approaches to DP have been devised, of which most have been designed to reduce the number of process steps. In this paper, we model several DP processes using our simulation software. Reflectivity control and resist profile optimization was maintained in the simulations using organic BARCs and spin-on multilayer stacks consisting of a silicon hardmask on top of a carbon underlayer. DP lithography results of these optimized tri- and quad-layer schemes are presented.

Implementation of a micro ball lens on a silicon optical bench using insoluble two-phase liquid immersion technology

This paper presents a two-phase liquid micro lens formation technology to implement a polymer micro ball lens. A UV-curable polymer is dispensed into a buffer liquid to form the ball lens. The buffer liquid provides a gravity-free condition so that the ball lens has a highly symmetric shape. The diameter of the ball lens is controlled by the volume of the dispensed polymer. This technology implements either a discrete optical component, or a ball lens integrated with a MEMS (micro electrical mechanical system) structure to form a SiOB (silicon optical bench). To demonstrate the feasibility of this study, ball lenses with diameters ranging from 200 to 600 µm and root mean square (RMS) surface roughness of about 10 nm are fabricated using a commercial UV-curable polymer. The average roundness of a 550 µm diameter ball lens observed from different angles is 3.3 ± 0.4 µm. The peak-to-valley and RMS wavefront errors of a 550 µm diameter ball lens measured by a Mach–Zehnder interferometer are 0.3744 waves (237 nm) and 0.0766 waves (48 nm), respectively. The measured back focal length is about 99 µm, and the associated effective focal length is about 351 µm. The integration of such polymer micro ball lenses with suspended micromachined Si3N4 structures to form the SiOB is also demonstrated.

Extension of Usable Spectral Range of Peltier Cooled Photodetectors

This paper provides update on development of the Peltier cooled detectors optimized for wavelengths above 13 „m. Initially, the devices made by Vigo were mostly used for uncooled detection of CO2 laser radiation. Over the years the performance and speed of response has been steadily improved. At present the uncooled or Peltier cooled photodetectors can be used for sensitive and fast response detection in the mid-wavelength and long-wavelength infrared spectral range. The devices have found important applications in IR spectrometry, quantum cascade laser based gas analyzers, laser radiation alerters and many other IR systems. Recent eorts were concentrated on the extension of useful spectral range to > 13 „m, as required for its application in Fourier transform IR spectrometers. This was achieved with improved design of the active elements, use of monolithic optical immersion technology, enhanced absorption of radiation, dedicated electronics, series connection of small cells in series, and last but not least, applying more ecient Peltier coolers. Practical devices are based on the complex HgCdTe heterostructures grown on GaAs substrates with metal-organic chemical vapor deposition technique with immersion lens formed by micromachining in the GaAs substrates. The results are very encouraging. The devices cooled with miniature 4 stage Peltier coolers mounted in TO-8 style housings show significant response at wavelength exceeding 16 „m.

32 nm Half Pitch Formation with High-Numerical-Aperture Single Exposure

According to the International Technology Roadmap for Semiconductors (ITRS), memory half pitch (hp) will reach 32 and 20 nm by 2012 and 2017, respectively. However, it is difficult to fabricate a sub-40 nm node using single-exposure technology with the currently available 1.35-numerical-aperture (NA) ArF immersion lithography. Although it is expected that either double patterning technology or extreme ultraviolet lithography will enable the realization of 32 nm hp, there are still many problems that need to be solved regarding cost reduction. Thus, the study of high-index fluid immersion technology should be pursued simultaneously. ArF water immersion systems with 1.35 NA have already been introduced for 40-nm-hp production. ArF immersion lithography using high-index materials is currently being studied for next-generation lithography. Currently, many studies are being undertaken in order to increase NA for a high-index fluid and a lens in immersion technology. The combination of LuAG (n = 2.14) and a third-generation fluid could be used to realize 1.55 NA. This combination of 0.25k1 and 32 nm hp can be obtained using single-exposure technology. In order to determine the feasibility of this process and possible process hurdles for this high-NA single-exposure technology, 32 nm hp with a 1:1 line and space pattern is tested. Various illumination conditions are tested to realize 1:1 32 nm hp, and the exposure and development conditions are varied to determine whether this single exposure can provide a processible window. As a result, 32 nm hp could be obtained by single-exposure technology with 1.55 NA.

Immersion Lithography: Photomask and Wafer-Level Materials

Optical immersion lithography utilizes liquids with refractive indices &gt;1 (the index of air) below the last lens element to enhance numerical aperture and resolution, enabling sub-40-nm feature patterning. This shift from conventional dry optical lithography introduces numerous challenges requiring innovations in materials at all imaging stack levels. In this article, we highlight the recent materials advances in photomasks, immersion fluids, topcoats, and photoresists. Some of the challenges encountered include the fluids' and photomask materials' UV durability, the high-index liquids' compatibility with topcoats and photoresists, and overall immersion imaging and defectivity performance. In addition, we include a section on novel materials and methods for double-patterning lithography—a technique that may further extend immersion technology by effectively doubling a less dense pattern's line density.

Influence of the mask magnification on imaging in hyper-NA lithography

Argon fluoride laser (ArF) lithography using immersion technology has the potential to extend the application of optical lithography to 45 nm half-pitch and possibly beyond. By keeping the same 4x magnification factor, the dimensions of the structures on masks are becoming comparable to the exposure wavelength or even smaller. The polarization effect induced by mask features is, however, an issue. The introduction of a larger mask magnification should be strongly considered when poor diffraction efficiencies from subwavelength mask features and the resulting image degradation would be encountered in hyper-NA lithography. The dependence of the diffraction efficiencies on mask pitch and illuminating angle are evaluated. The near-field intensity and phase distributions from the mask are calculated. The imaging performance of 4x and 8x masks for the sub-45 nm node are explored. A rigorous coupled-wave analysis is developed and employed to analyze the optical diffraction from the 3D topographic periodic features.