Academic literature on the topic 'Interface between anti-Reflective coating and silicon'

The article examines the problems of thermal oxidation of silicon. Oxidation plays an important role in planar technology, which in turn is the basis of the technology of silicon integrated circuits, photodetectors and other solid-state electronics. During our production of silicon p-i-n photodiodes, a number of systematic types of defects and deterioration of product parameters caused by the degradation of masking or anti-reflective coatings during the manufacturing process were observed. A decrease in the insulation resistance of responsive elements in multi-element photodiodes was observed, which contributed to the increase of dark currents. A decrease in the responsivity of the products due to the degradation of the thickness or structure of the anti-reflective coating during technological operations, etc., was also revealed. It was established that the reason for the decrease in insulation resistance is the formation of inversion layers at the Si-SiO2 interface, the presence of which can be detected when measuring CV-characteristics. It was also established that chemical treatment of substrates with SiO2 in boiling acid solutions helps to reduce the thickness of the oxide. To avoid deviation of the thickness of the film from the condition of minimum reflection, it is necessary to grow a thicker layer of anti-reflective coating. It is noted that when etching the oxide during photolithography or when removing the PSG/BSG in hydrofluoric acid, it is not permissible to remove the cassette with plates from the solution for a long time, as this leads to uneven etching of the film due to the flow of the herb on the surface of the substrate. The causes of defect formation in Si and SiO2 during oxidation are given. Thus, with improper mechanical and chemical processing of the plates, cristobalite inclusions may form in the film during oxidation. Cristobalite has a higher density than quartz glass, and the boundaries between amorphous regions and denser crystalline regions represent voids, which can be filled both by impurities from the surface and by the diffusant in the diffusion process. Also, during oxidation in silicon, packing defects are often formed. Centers of defect genesis can be mechanical damage to the plate surface or growth defects.

Water uptake, adhesion and corrosion performance of silicone-epoxy coating on 2024 Al-alloy treated with different GLYMO were systematically studied by gravimetry, electrochemical measurements, DSC, pull-off adhesion and salt spray tests. The results showed that GLYMO not only enhanced the cross-linking of the silicon-epoxy coating but also enhanced the bonding between the coating and the Al-alloy interface. This gives the coating better wet adhesion, less water absorption and improves the corrosion resistance of the coating. The micro-nano silane layer, preferentially between the coating and Al-alloy oxide layer, was validated by the model of the water concentration jump.

The effects of anti-reflective coatings (ARC) on organic light emitting diode (OLED) optical characteristics are reported in this paper. The light output produced from the OLED is not 100%. But the emitted light is trapped due to various Modes. The losses at the glass air substrate interfaces of an OLED are addressed in this work. The Anti-Reflective coatings increase the light output by reducing OLED reflections at the interface between glass and air. The Finite Difference Time Domain (FDTD) method and the Fresnel theory have been used to design the device and study the effects on OLED of the Single Layer Anti-Reflective Coating (SLAR) and Double Layer Anti-Reflective Coating (DLAR). The thicknesses and refractive indices of the layers of the anti-reflective coatings were optimized. We also compared the light out coupling power efficiency of the SLAR coated OLED with that of an OLED with a DLAR coating and also with Conventional OLED. The results show that the enhancement in light output efficiency of the DLAR coated OLED was slightly higher than that of the SLAR coated OLED.

In recent years, inspired by “biomimicry”, superhydrophobic surfaces have gained significant attention. Superhydrophobic surfaces demonstrate notable advantages in addressing interfacial issues, and superhydrophobic coatings exhibit excellent waterproofness, anti-fouling, self-cleaning, anti-corrosion, and additional capabilities, making them promising next-generation waterproof materials. However, the complex preparation process, coupled with poor wear resistance and environmental durability, severely limits their practical applications. Therefore, this article started from simplifying the preparation process and improving the durability of the coatings. Epoxy resin (E51) was used as the film-forming material, and carbon nanotubes (CNTs) and dual-sized SiC particles (nano-SiC and micro-SiC) were used as the fillers. Room temperature vulcanized silicone rubber (RTV) was used as a binder interacting with epoxy resin to promote the interface interaction between the fillers and the polymers. This process resulted in the successful preparation of superhydrophobic coatings with outstanding comprehensive performance. When the ratio of μ-SiC to n-SiC was 1:1, the prepared coating exhibited the best superhydrophobic properties with a water contact angle (WCA) of 167.4° and a sliding angle (SA) of 4.6°. Even after undergoing severe mechanical tests, such as sandpaper abrasion for 1000 cycles, sand impact for 100 cycles, cross-cut test, and tape-peeling for 70 cycles, the coatings still maintained their non-wetting Cassie-Baxter state. Furthermore, even after immersion in strong acid, strong alkali and 3.5 wt% NaCl solutions for 6 days, keeping at 500 ℃ for 2 hours, and exposure to ultraviolet for 6 days, the coatings still exhibited excellent superhydrophobicity. This suggested that the prepared coating had excellent chemical stability and high-temperature resistance. In addition, the superhydrophobic coating exhibited exceptional capabilities in self-cleaning, anti-corrosion, anti-icing, and de-icing properties. Furthermore, this coating, applicable to diverse substrates including board, steel, paper, and glass, demonstrated an impressive water contact angle (WCA) and sliding angle (SA). The spraying method offers the benefits of simplicity and cost-effectiveness. This is poised to significantly broaden its practical applications in various fields, including construction, transportation, and the chemical industry.

Substrate cleaning prior to coating has a strong influence on the performance of the optical component. Exemplary, none or inadequate cleaning reduces the resistance against laser irradiation drastically. Especially in laser components coated with anti-reflective layers, the interface between substrate and coating is one of the most limiting factors. This study investigates different precision cleaning processes and their influence on the laser resistance of ion-beam sputtered anti-reflective coatings. Therefore, a SiO2/Ta2O5 multilayer anti-reflective coating for a wavelength of 1064 nm and a normal angle of incidence was deposited onto high-quality fused silica substrates. Prior to deposition, the substrates were cleaned with various cleaning processes using different solutions and ultrasonic frequencies. To characterize the cleaned surface quality, the surfaces were analyzed with respect to root-mean-square (RMS) roughness and particle density. Laser damage was measured using a 1064 nm ns-pulsed laser test bench. It was found that an alcoholic pre-clean is recommendable to prevent laser damage caused by organic films remaining from the polishing process. The applied ultrasonic frequencies strongly influenced the particle density down to the sub-micrometer range and in consequence, the laser-induced damage threshold (LIDT). Ultrasonic cleaning at excessive power levels can reduce laser resistance.

This study investigates how to improve the anti-adhesion issues between Silicon mold and nanostructures of hard polydimethylsiloxane (H-PDMS). A Silicon mold with different depths and widths was made using a focused ion beam (FIB). During the soft-lithography molding process, anti-adhesion layers were needed between the Silicon mold and H-PDMS samples to prevent the de-molding failure caused by the adhesion issues between the interfaces. This study adopts three methods to deposit anti-adhesion layers, such as liquid immersion, vapor deposition, and fluorine-doped diamond-like carbon (F-DLC) film. Perfluorooctyl-trichlorosilane (PFOTCS) was used as a mold-releasing agent for the liquid immersion and vapor deposition methods. The contact angles between each film were measured to determine the effect of anti-adhesion on the molding process. In addition, atomic force microscopy (AFM) was used to measure the adhesion force between the H-PDMS and anti-adhesion layers. The results show that the coatings of anti-adhesion layers are an effective approach to improve the formability of molding.

Silicone elastomer coatings have shown successful fouling release ability in recent years. To further enhance the design of silicone coatings, it is necessary to fully understand the mechanisms that contribute to their performance. The objective of this study was to examine the relationship between the molecular weight of polydimethylsiloxane (PDMS) and antibioadhesion efficiency. PDMS-based coatings were prepared via a condensation reaction, with a controlled molecular weight ranging from 0.8 to 10 kg·mol−1. To evaluate changes in surface wettability and morphology, contact angle experiments and atomic force microscopy (AFM) were performed. Finally, the antibioadhesion and self-cleaning performance of PDMS coatings was carried out during in situ immersion in Lorient harbor for 12 months. Despite small variations in surface properties depending on the molecular weight, strong differences in the antibioadhesion performance were observed. According to the results, the best antibioadhesion efficiency was obtained for coatings with an Mn between 2 and 4 kg·mol−1 after 12 months. This paper provides for the first time the impact of the molecular weight of PDMS on antibioadhesion efficiency in a real marine environment.

Microfabrication techniques used in semiconductor industry deliver high yield of devices and silicon microtechnologies undoubtedly have a reputation of a well-established platform for manufacture. A Silicon-wafer is the most commonly used substrate due to its low-cost; therefore for decades several protocols have been developed in order to process this particular material for micro-nano electronics. Today, it is possible to manufacture ultramicro-nano scale devices with multiple steps of lithography, deposition, and lift-off. Clearly, such progress of microsystems has been one of the major interests of biology-based research fields due to the need for small-reproducible devices with appropriate interface features, in particular for biosensing-applications. Biosensing technologies have an important contribution to a daily basis life with the examples of glucometers, pregnancy tests, Covid-19 tests, etc. Microtechnologies combined with sensing systems are clearly a rising-star due to several benefits of microfabrication protocols such as excellent reproducibility, miniaturization capabilities, low-cost and design flexibility for device fabrication. Establishment of a successful fabrication route of ultramicro devices with high reproducibility is a challenge. Figure1 shows an example fabrication-flow of one of our devices. We have developed several successful fabrication flows for device manufacturing and we have developed several designs of gold chips based on band-electrode-array[1], disk-electrode-array[2], and multiplexing[3] for varying (bio)sensing applications. Figure2 shows a series of SEM images of designed, fabricated and foam-modified devices. One of the significant key of using such tiny devices is the electrochemical reproducibility of the gold surfaces to establish a successful sensing platform. Therefore we assessed the effect of several cleaning protocols on the electrochemical characteristics of ultramicro-electrode-devices. As an example, Figure3a shows one of the 6-sensing-electrodes on a multiplexed-device(1µm-width,45µm-length). After the cleaning protocol of chip, we studied cyclic voltammetry in a redox probe(5mM Fe(CN)6 3–/4– in 1M KCl). Clearly, applied protocol provides reproducible redox-active sensing-electrode surfaces therefore; we obtained overlapping voltammograms of 6-electrode-on-chip(Figure3b). We also investigated the surface morphology of the gold surface(Figure3c). We discovered that the cleaning protocol increases surface-roughness which may lead a redox-active surface. One another key aspect of our study is the application of these tiny devices. We in particular studied miniaturization of hydrogen-bubble template with chips to explore scaling-down limits of in situ template. Figure2 represents many of designs applied with in situ template studied in highly acidic solution under high negative voltages. We explored the electro-catalytic activity of these foam deposits. For example, Figure3d shows one of the sensing electrodes on multiplexed-device after Cufoam deposition. This device is capable of oxidizing glucose in 0.1M NaOH[1a, 4] at a voltage of +0.8V(Figure3e). Therefore we assessed the linear-range between glucose concentration and device response(Figure3f). One of the parameters we have studied was reusability of multiplexed device and Figure3g shows 10-subsequest measurements studied with a single device. We have shown the application of such devices in whole serum samples and also river water for chemical oxygen demand concentration determination. The other application we have been developing via multiplexing is immunosensor development for animal health. We have developed a simple anti-fouling matrix which allowed us to study in a complex matrix. Figure 4a summarizes the development protocol of antifouling matrix which was studied with CV after fresh antifouling coating and after incubation with either 5% BSA or serum overnight. Figure 4b shows the SEM image of one of the sensing electrode on chip after the gold deposition. We use these needle-like gold depositions as a high surface area substrate where we apply the antifouling matrix. Then, via carbodiimide chemistry we immobilized anti-Haptoglobin antibodies onto surface which is specific to haptoglobin protein (one of the immunosensors on chip). With this study we are aiming to detect several biomarkers from milk of cow after calving. This publication has emanated from research conducted with the financial support of Science Foundation Ireland (SFI) and the Department of Agriculture, Food and Marine on behalf of the Government of Ireland under Grant Numbers [16/RC/3835), DAFM stimulus AgriSense II Grant Number 17/RD/US-ROI/56, and EU Horizon 2020 (DEMETER 857202). [1] aV. B. Juska, A. Walcarius, M. E. Pemble, Acs Appl Nano Mater 2019, 2, 5878-5889; bV. B. Juska, M. E. Pemble, Analyst 2020, 145, 402-414. [2] V. Buk, M. E. Pemble, Electrochimica Acta 2019, 298, 97-105. [3] aL. A. Wasiewska, I. Seymour, B. Patella, R. Inguanta, C. M. Burgess, G. Duffy, A. O'Riordan, Sensors and Actuators B: Chemical 2021, 333, 129531; bB. O'Sullivan, B. Patella, R. Daly, I. Seymour, C. Robinson, P. Lovera, J. Rohan, R. Inguanta, A. O'Riordan, Electrochimica Acta 2021, 395. [4] V. B. Juska, G. Juska, J Chem Technol Biot 2021, 96, 1086-1095. Figure 1

Anti-reflective coating (ARC) application is continuously being developed extensively and widely for the manufacture of coatings on the surfaces of optical devices which are hugely essential, desirable, and required, particularly on silicon solar cells. Single layer ARC is sufficient, but double layer ARC tremendously enhances solar cell efficiency by covering a wider range of the solar spectrum. Magnesium fluoride, MgF2 and silicon dioxide, SiO2 are the ARC coatings used in this work, with wavelengths in the range from 300 to 1200 nm. The optical properties of bilayer ARC coatings were obtained by varying the thickness of the double coatings and see how the ARC effects Si solar cells. Wafer ray tracer was used in PV Lighthouse software to simulate and model MgF2 and SiO2 bilayer ARC coatings in order to fully understand the performance and impacts of the coatings on Si solar cells. This simulation work contains the analysis of reflection, absorption, transmission, and Jmax, which have been compared to many other theoretical results gathered from other studies and researches. To conclude, the absorption of the wavelength is highest between 500 nm to 900 nm leads to lowest reflection. The output shows that bilayer anti-reflective coatings with the thickness of 75 nm MgF2 and SiO2 are much more effective where the value of Jmax is reach 32.80 mA/cm2. The Jmax enhancement compare to reference is 27.13% is achieved.

We have theoretically demonstrated an efficient way to improve the optical properties of an anti-reflection coating (ARC) and an intermediate reflective layer (IRL) to enhance tandem solar cell efficiency by localizing the incident photons’ energy on a suitable sub-cell. The optimum designed ARC from a one-dimensional ternary photonic crystal, consisting of a layer of silicon oxynitride (SiON), was immersed between two layers of (SiO2); thicknesses were chosen to be 98 nm, 48 nm, and 8 nm, respectively. The numerical results show the interesting transmission properties of the anti-reflection coating on the viable and near IR spectrum. The IRL was designed from one-dimensional binary photonic crystals and the constituent materials are Bi4Ge3O12 and μc-SiOx: H with refractive indexes was 2.05, and 2.8, respectively. The numbers of periods were set to 10. Thicknesses: d1 = 62 nm and d2 = 40 nm created a photonic bandgap (PBG) in the range of [420 nm: 540 nm]. By increasing the second material thickness to 55 nm, and 73 nm, the PBG shifted to longer wavelengths: [520 nm: 630 nm], and [620 nm: 730 nm], respectively. Thus, by stacking the three remaining structures, the PBG widened and extended from 400 nm to 730 nm. The current theoretical and simulation methods are based on the fundamentals of the transfer matrix method and finite difference time domain method.

Abstract The topic of this work is the sequential use of Solid Immersion Lenses (SILs), created in bulk silicon in less than 20 minutes of processing time, using a focused ion beam and a bitmap milling process. Fibbed SILs can be removed by polishing, and the silicon back surface resumes a perfect planar shape for further backside analysis or the creation of more SILs. The influence of the progressively thinner sample thickness on the magnification of the SIL was analyzed. As fibbed SILs in this work are about 1.4 µm thick and have an additional magnification of 2.4, a second process after removal has been found to decrease magnification not more than 20%. The presence of interference rings in the SIL image could be almost completely removed by anti-reflective coating. Photon emission microscopy, performed using fibbed SILs, allowed to clearly distinguish between sources that were separated by 240 nm wide structures.