Effect Of Etching Parameters Research Articles

Оценка влияния параметров травления на характеристики однопроводных и многопроводных линий передачи

Modernization of radio-electronic equipment leads to the need to improve the methods of manufacturing the components that are a part of it. Printed circuit boards are predominantly manufactured using subtractive methods. Under conditions of constant miniaturization, it is necessary to consider the impact of conductor subtractive etching on the performance of the fabricated prototype. In this paper, the effect of etching parameters on the performance of single and coupled microstrip lines is evaluated. An algorithm for evaluating the influence of etching parameters on the characteristics of the considered structures is proposed. In the future it is planned to conduct a laboratory experiment with the extraction of etching coefficients and evaluation of their influence on the characteristics of the considered structures.

Synthesis and lithium ion storage performance of novel two dimensional vanadium niobium carbide (VNbCTx) MXene

Two-dimensional double transition metal carbides/nitride with unique out-of-plane arrangement of two metal atoms is emerging as a new pseudocapacitor material and attracting wide attention in the field of energy storage. Herein, fabrication of a novel 211-phase vanadium niobium carbide (VNbCTx) MXene by selectively etching the Al atomic layer from its VNbAlC MAX phase is reported for the first time. Effect of etching parameters on the microstructure, crystallinity, and electrochemical property of multilayer VNbCTx is examined. As the electrode material of lithium ion batteries, VNbCTx show a higher specific capacity of 520.5 mAh g−1 at 0.1 A g−1 and promising cycle stability. This work provides additional understanding about the synthesis and storage performance of double transition metal MXene, which will benefit the development of novel double transition metal MXene for energy storage applications.

Enhanced photocatalytic activities of silicon nanowires/graphene oxide nanocomposite: Effect of etching parameters

Homogeneous and vertically aligned silicon nanowires (SiNWs) were successfully fabricated using silver assisted chemical etching technique. The prepared samples were characterized using scanning electron microscopy, transmission electron microscopy and atomic force microscopy. Photocatalytic degradation properties of graphene oxide (GO) modified SiNWs have been investigated. We found that the SiNWs morphology depends on etching time and etchant composition. The SiNWs length could be tuned from 1 to 42 µm, respectively when varying the etching time from 5 to 30 min. The etchant concentration was found to accelerate the etching process; doubling the concentrations increases the length of the SiNWs by a factor of two for fixed etching time. Changes in bundle morphology were also studied as function of etching parameters. The SiNWs diameter was found to be independent of etching time or etchant composition while the size of the SiNWs bundle increases with increasing etching time and etchant concentration. The addition of GO was found to improve significantly the photocatalytic activity of SiNWs. A strong correlation between etching parameters and photocatalysis efficiency has been observed, mainly for SiNWs prepared at optimum etching time and etchant concentrations of 10 min and 4:1:8. A degradation of 92% was obtained which further improved to 96% by addition of hydrogen peroxide. Only degradation efficiency of 16% and 31% has been observed for bare Si and GO/bare Si samples respectively. The obtained results demonstrate that the developed SiNWs/GO composite exhibits excellent photocatalytic performance and could be used as potential platform for the degradation of organic pollutants.

THE EFFECTS OF ACID CONCENTRATION, ETCHING TEMPERATURE AND TIME ON THE SURFACE MORPHOLOGIES OF TI6AL4V

Within this work, the effect of etching parameters on the surface morphology of Ti6Al4V alloy was investigated. For this purpose, different temperatures, different proportions of HCl-H2SO4 acid mixtures and different etching times were used for the etching process. After etching, XRD analyses, SEM images and surface roughness values of the samples were presented. It was observed that increasing etching temperature facilitated the formation of pore structure on the surface, but after a certain temperature, the increasing temperature started to show negative effects. When all the microstructure images are considered, it is understood that acid concentration and etching time are effective parameters besides temperature difference.

Investigation of Silicon Nanowires Produced by Metal-Assisted Chemical Etching Method

Silicon nanowires (SiNWs) have a strong potential in many fields. The investigation of fabrication methods for SiNWs has attracted much attention in semiconductor applications. This paper proposes a metal-assisted chemical etching (MACE) method as a low-cost and simple method for fabrication of SiNWs. This method is based on the electroless metal deposition (EMD) principle. We have studied the conditions of MACE method for fabrication of SiNWs on (100) p-type silicon wafer. A 0.005 AgNO3 and 4.8 M HF solution is used for metal-assisted depositing of the silver nanodots. The etching process is achieved by etchant solution consisting of 4.8 M HF and different concentrations of H2O2. The effect of etching parameters, such as etching time, H2O2 concentration and the dipping time, are investigated. Taguchi with L9 orthogonal array is used by software package MINITAB 17 for designing the experiments. The results of scanning electron microscopy (SEM) observations shows the formation of the silicon nanowires. The effect of the different conditions on the size of the SiNWs is analyzed using S/N ratio and ANOVA approach. The results show that etching time was the most significant factor in the SiNWs fabrication.

Implementation of slow and smooth etching of GaN by inductively coupled plasma * * Project supported by the National Key R&D Program of China (No. 2017YFB0403001) and the National Natural Sciences Foundation of China (No. 61404134).

Slow and smooth etching of gallium nitride (GaN) by BCl3/Cl2-based inductively coupled plasma (ICP) is investigated in this paper. The effects of etch parameters, including ICP power, radio frequency (RF) power, the flow rate of Cl2 and BCl3, on GaN etch rate and etch surface roughness RMS are discussed. A new model is suggested to explain the impact mechanism of the BCl3 flow rate on etch surface roughness. An optimized etch result of a slow and smooth etch surface was obtained; the etch rate and RMS were 0.36 Å/s and 0.9 nm, respectively.

Preparation of structured surfaces for full-spectrum photon management in photovoltaic-thermoelectric systems

Micro-structured surfaces for broadband and omnidirectional photon management in photovoltaic-thermoelectric systems are fabricated on the silicon wafer by inductively coupled plasma etching with self-assembly polystyrene spheres mask, KOH solution etching and magnetron sputtering method. The Si antireflection structure coated with SiO2 film is fabricated on the top surface of Si substrate to enhance the absorption of the photons with wavelengths of 0.3–1.1µm is increase the electron-hole pairs. The TiO2/SiO2 films as the back-antireflection coating are deposited at the back of Si wafer to improve the transmission of solar energy within the wavelength range of 1.1–2.5µm. The absorbed photons within the wavelength range of 0.3–1.1µm can directly be converted into electricity power by Si solar cells while the photons with wavelengths of 1.1–2.5µm transmit through the cells and are utilized by thermoelectric modules. The effects of etching parameters on the spectral features are investigated to get the optimal etching parameters. With the optimal etching parameters, the surface absorption for the wavelengths of 0.3–1.1µm is significantly increased to above 0.95 due to the effective graded refractive index and the transmission is obviously enhanced for the wavelengths of 1.1–2.5µm. The incident angle-sensitivity and polarization-sensitivity of the fabricated structured surfaces are analyzed. The results indicate that these surfaces can be selected for photovoltaic-thermoelectric systems due to their high omnidirectional absorption and transmission of the photons as well as the favorable polarization-insensitivity within the expected wavelength ranges.

Sustainability Analysis of Silicon Nanowire Fabrication for High Performance Lithium Ion Battery Anode

Silicon nanowires (SiNWs) are synthesized by two-step metal-assisted chemical etching (MACE) using different etching parameters including AgNO3 concentrations (5/20/50mM) and H2O2 concentrations (0.03/0.1/0.3M). Diameter distributions of synthesized SiNWs with different parameters are analyzed. Gas emissions and nanoparticle wastes in SiNWs synthesis process are theoretically calculated and experimentally tested. The effects of etching parameters on etching rate are investigated.▪Fig. A.. Gas emissions with different etching conditions. (a) H2O2 0.3M with variable AgNO3 concentrations (5/20/50mM); (b) AgNO3 20mM with variable H2O2 concentrations (0.03/0.1/0.3M).

Crystal structure induced residue formation on 4H-SiC by reactive ion etching

The (0001¯) C face of 4H-SiC wafer was etched by reactive ion etching in SF6/O2 plasma. The effect of etching parameters, such as work pressure, SF6:O2 ratio and etching time, on the residue formation were systematically investigated. The residue morphologies were observed by scanning electron microscopy and atomic force microscopy, respectively. The residues have spike shape and their facets are defined as {11¯02¯} crystal planes. They are formed at beginning of the etching and no new spikes are generated as prolonging etching time. Both work pressure and SF6:O2 ratio play significant role in the spike formation. The residues can be eliminated completely by increasing the SF6:O2 ratio and work pressure. On the basis of experimental results and of 4H-SiC crystal structure, the spike formation model is proposed.

Effects of etching parameters on ZnO nanotubes evolved from hydrothermally synthesized ZnO nanorods

This paper reports fabrication and characterization of ZnO nanotubes on Au cylindrical spirals. Highly oriented single-crystalline ZnO nanorods were hydrothermally synthesized on Au cylindrical spirals and were etched in NaOH solution to form nanotubes. Effects of etching parameters on the lengths, wall thicknesses and morphologies of the ZnO nanotubes were studied with the etching period, etching temperature and NaOH concentration regulated respectively. It turns out that the etching parameters affect significantly the morphologies of the ZnO nanotubes but negligibly the lengths and wall thicknesses. The surfaces of the ZnO nanotube-coated Au cylindrical spirals tend to be Gaussian rough ones as the etching parameters become larger. Adjusting the etching temperature readily gives rise to perfect ZnO nanotubes. The results are beneficial for large-scale preparation of ZnO nanotubes with controllable sizes and morphologies in nanodevices.

Broadband quasi-omnidirectional sub-wavelength nanoporous antireflecting surfaces on glass substrate for solar energy harvesting applications

A cost effective, facile and scalable method to fabricate the stable broadband antireflective (AR) surface on glass substrates for solar energy applications is still a challenge. In this paper, we have demonstrated a simple and non-lithographic method to fabricate the broadband quasi-omnidirectional AR nanoporous surface on glass substrates by hydrofluoric (HF) acid based vapor phase etching method. Both-sides etched sodalime glass substrate under optimized conditions showed broadband enhanced transmittance with maximum total transmittance of ~97% at 598nm. The measured transmittance exceeds by ~5.4% as compared to plain glass (91.6%). Field emission scanning electron microscopy results showed that an AR nanoporous surface with graded porosity was formed on sodalime glass substrate after etching. Due to the graded porosity, the fabricated nanoporous surface on sodalime glass substrate showed excellent broadband enhanced transmittance, and exhibited low reflectance <2.8% over a wide range of incidence angles (8–48°). The mechanism of nanostructured surface formation and the effect of etching parameters on transmittance have been discussed in detail. To get more insight, the theoretical transmittance of the optimized sample has been determined by finite difference time domain simulation, which confirms a good agreement of AR property with the experimental results. Furthermore, these AR nanoporous surface showed good adhesion property, excellent thermal and chemical stability, and exhibited outstanding stability against outdoor exposure. These properties signify its strong potential in various solar energy devices.

Preparation, microstructure characterisation and corrosion behaviour of directionally grown TaSi2 fibre arrays with sharp tip fabricated by selective wet etching

Abstract Directionally solidified Si–TaSi2 eutectic composite is selectively etched to fabricate well aligned TaSi2 tip array for field emission application. The effect of etching parameters on TaSi2 tip structure, and its corrosion behaviour in HNO3/HF solution are investigated. At the optimised condition (HNO3/HF = 5 for 50 min), sharp TaSi2 tips with curvature radius of 18 nm and homogenous distribution are obtained, which greatly improves the figure of merit associated with field emission current. The TaSi2 fibre presents smaller dissolution rate in the HNO3/HF solution than Si matrix. The formation mechanism of etching pit on the Si matrix surface is also discussed.

Dry Etching Characteristics of Amorphous Indium-Gallium-Zinc-Oxide Thin Films

Amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) backplane technology is the best candidate for flat panel displays (FPDs). In this paper, a-IGZO TFT structures are described. The effects of etch parameters (rf power, dc-bias voltage and gas pressure) on the etch rate and etch profile are discussed. Three kinds of gas mixtures are compared in the dry etching process of a-IGZO thin films. Lastly, three problems are pointed out that need to be addressed in the dry etching process of a-IGZO TFTs.

Inductively coupled plasma etching to fabricate sensing window for polymer waveguide biosensor application

Integrated polymeric waveguide biosensors are usually used for the detection of chemical/biological samples. To improve the sensitivity of the conventional waveguide sensors with only one sensing surface, we design and fabricate an improved sensing window with three sensing surfaces based on inductively coupled plasma etching method, whose sensitivity can be enhanced by a factor of 2.8 in theory. The effects of etching parameters, especially the antenna power, the bias power and the O2 flow rate were systematically studied and the parameters were optimized to fabricate the sensing window. A single-mode balanced Mach–Zehnder interferometer waveguide biosensor with the improved sensing window was fabricated under this optimum etching condition, and presented a higher sensitivity than that of the sensor with conventional sensing window. This type of sensing window will be very useful in polymer waveguide biosensor devices.

Optimization of metal-assisted chemical etching process in fabrication of p-type silicon wire arrays

The metal-assisted chemical etching (MCE) has attracted great attention because of the advantages such as simple and large area process, low-cost and compatible with existing semiconductor technology. We have achieved optimization conditions about two kinds of MCE method for fabrication of p-type silicon wire arrays. First one is one-step MCE that used AgNO 3 and BOE solution and second is two-step MCE in which silicon etching proceeds by BOE and H 2O 2 solution after depositing Au by thermal evaporation. Particularly, the effect of etching parameters, such as etching time and AgNO 3 concentration in one-step MCE and metal catalyst thickness and etching solution temperature in two-step MCE on fabrication of silicon was investigated a morphology, length and etch rate of silicon wire. Finally, we have found important factors for fabrication of uniform and well aligned p-type silicon wire by MCE.

Focused electron beam induced etching of silicon using chlorine

A new beam-assisted process for removing silicon from a surface in the nanometer scalein a conventional scanning electron microscope is presented. This approach isbased on focused electron beam induced etching with pure chlorine gas being usedas the precursor. In contrast to the established etching process using a focusedion beam (with or without the addition of a precursor), no amorphizationand gallium implanting of the substrate takes place. The observed low etchrates facilitate removal with sub-nanometer precision. No spontaneous etchingof silicon as in the case of xenon difluoride was observed. Etch rates of up to4 nm min − 1 could be achieved as well as a minimum feature size of below 80 nm. The effect of etchingparameters like electron beam energy, electron beam accelerating voltage or pixelspacing were systematically examined. Finally, the underlying etching mechanism interms of secondary electron interactions and precursor replenishment is discussed.

Nanometer-sized etching of magnetic tunnel junction stack for magnetic random access memory

High-density plasma reactive ion etching of MTJ stack was investigated in an inductively coupled plasma of Cl 2/Ar and Cl 2/O 2/Ar gas mixes. Thin TiN hard mask was employed and the etching proceeded at ambient temperature. The effect of etch gas on the etch profiles of MTJ stack was examined by varying the gas concentration. In addition, the effects of etch parameters on the etch profiles and magnetic properties of MTJ stacks were investigated. The highly anisotropic etching of MTJ stack arrays with 200×200 and 100×100 nm 2 dimensions was successfully achieved.

Fabrication of 1 ×8 Multimode-Interference Optical Power Splitter based on InP Using CH4/H2 Reactive Ion Etching

1 ×8 multimode-interference (MMI) power splitters with a weakly guided ridge structure based on an InGaAsP/InP material for 1.55 µm operations were designed and fabricated. To determine the optimum etching condition of InP in CH4/H2 plasma for the formation of MMI power splitters, the effects of etching parameters, such as flow rates of constituent gases, rf power, and process pressure on the etch rate and surface morphology were investigated. The fabricated 3-µm-wide adjacent straight waveguides have propagation losses of 2.91 dB/cm at 1.55 µm for transverse electric (TE) polarization. The device performances in terms of the thickness of the upper cladding layer were theoretically and experimentally compared. The polarization dependence of the MMI power splitters was investigated. For TE [transverse magnetic (TM)] polarization, the excess loss of the devices at an operating wavelength of 1.55 µm was 1.02 dB (1.95 dB) and the splitting ratio was 0.68 dB (1.13 dB).

Anisotropic etching characteristics of platinum electrode for ferroelectric capacitor

The effect of etch parameters of platinum etching using Cl/sub 2//CO plasma on the etching properties and the etch profiles was investigated. The etching characteristics with respect to substrate temperature are different in two temperature regions below and above 210/spl deg/C and significantly depended on Cl/sub 2/ concentration in each temperature region. The etch rates of Pt were enhanced suddenly at the substrate temperature of around 210/spl deg/C when Cl/sub 2/ concentration is 50-80%. The etch rates of Pt below 210/spl deg/C did not change much with increasing temperature. The selectivity of Pt over SiO/sub 2/ was governed by the etch rate of SiO/sub 2/ in the lower temperature region but determined by the etch rates of Pt in the higher temperature region. The anisotropy of etch profiles was high enough to achieve vertical pattern without etch residues in the lower temperature region for the application in fabricating 1-Gbit era. In the higher temperature region, however, the slopes of etch profiles due to the volatile products of Pt were found. XPS was used to analyze the surface atomic compositions after various etching treatments.