Effects Of Etching Conditions Research Articles

P‐7.11: Effect of etching conditions, MoNb thickness on gate profile and CD Bias of ADS Pro TFT

P‐7.11: Effect of etching conditions, MoNb thickness on gate profile and CD Bias of ADS Pro TFT

Effect of etching conditions on electroless Ni-P plating of 3D printed polylactic acid

ABSTRACT The aim of this study is to investigate the effect of the etching conditions on some technologically important properties of the Ni-P coating deposited by an electroless process on 3D printed PLA and PLA-flex. The influences of the temperature and the concentration of the etching sodium hydroxide solution on the deposition rate, composition, adhesion, wetting and roughness of Ni-P coatings were determined. The studies revealed that the high temperature and concentration of the etching solution did not improve the coating properties. In regard to the wetting and adhesion properties of the Ni-P coating, the best results were obtained at concentrations of the etching solution from 100 to 200 g L−1 NaOH and at a temperature of 20–40°C. These conditions allow good wetting of the freshly deposited nickel. Etching plays an important role not only in improving adhesion, but also has an effect on the composition and thickness of the nickel layer.

Influence of the carrier wafer during GaN etching in Cl2 plasma

In this study, we have performed a thorough characterization of the GaN surface after etching up to 100 nm in Cl2 plasma under various bias voltages and according to the carrier wafer used (Si, SiO2, Si3N4, and photoresist). The objective of this article is to evaluate the etch damage and contamination of the GaN surface when materials with other chemical nature are present during etching. The effects of etching conditions on surface morphology and chemical compositions of etched GaN films are studied in detail using XPS and AFM measurements. To this aim, a universal methodology is proposed to estimate accurately by XPS the stoichiometry of the GaN surface exposed to reactive plasmas when only an Al Kα x-ray source is available. The results indicate that the GaN etching mechanisms are very sensitive to the chlorine radical density present in the plasma, the latter being strongly influenced by the carrier wafer. Substrates that are more chemically reactive with Cl2 plasma such as silicon or photoresist compared to SiO2 or Si3N4 will lead to a greater loading of atomic chlorine, which in turn will lead to lower GaN etch rates. Moreover, the GaN surface contamination will depend on the etch by-products ejected by the carrier wafer. The GaN surface exposed to Cl2 plasma shows a Ga-depleted surface because of the more important reactivity of Cl with Ga rather than N, except in the SiO2 carrier wafer case. In this latter case, the formation of Ga–O bond limits the Ga removal. Regarding the surface roughness, it seems that the contaminants play a little role in the roughness formation except for the oxygen released by the SiO2 carrier wafer. On the other hand, the surface roughness evolution is clearly driven by the chlorine radical flux reaching the GaN surface. At low bias voltage, a preferential crystalline orientation etching driven by the Cl radicals leads to the formation of hexagonal shaped defects that are associated to screw-type threading dislocations already present in the pristine GaN material. At higher bias, the enlargement of the defects is limited, leading to a very low surface roughness value but to amorphized surfaces.

Dynamic secondary ion mass spectroscopy of Au nanoparticles on Si wafer using Bi3+ as primary ion coupled with surface etching by Ar cluster ion beam: The effect of etching conditions on surface structure

Wet-chemically synthesized Au nanoparticles were deposited on Si wafer surfaces, and the secondary ions mass spectra (SIMS) from these samples were collected using Bi3+ with an energy of 30 keV as the primary ions. In the SIMS, Au cluster cations with a well-known, even-odd alteration pattern in the signal intensity were observed. We also performed depth profile SIMS analyses, i.e., etching the surface using an Ar gas cluster ion beam (GCIB), and a subsequent Bi3+ SIMS analysis was repetitively performed. Here, two different etching conditions (Ar1600 clusters of 10 keV energy or Ar1000 of 2.5 keV denoted as “harsh” or “soft” etching conditions, respectively) were used. Etching under harsh conditions induced emission of the Au-Si binary cluster cations in the SIMS spectra of the Bi3+ primary ions. The formation of binary cluster cations can be induced by either fragmentation of Au nanoparticles or alloying of Au and Si, increasing Au-Si coordination on the sample surface during harsh GCIB etching. Alternatively, use of the soft GCIB etching conditions resulted in exclusive emission of pure Au cluster cations with nearly no Au-Si cluster cation formation. Depth profile analyses of the Bi3+ SIMS combined with soft GCIB etching can be useful for studying the chemical environments of atoms at the surface without altering the original interface structure during etching.

Effects of etching conditions on surface morphology of periodic inverted trapezoidal patterned Si(100) substrate

In this paper, the anisotropic etching process of Si(100) wafers in tetramethyl ammonium hydroxide (TMAH) solution with isopropyl alcohol (IPA) is investigated in detail. An inverted trapezoidal pattern is developed. A series of experiments are performed by changing TMAH concentration, IPA concentration, etching temperature and etching time. The structure of inverted trapezoidal patterns and roughness of the bottom surface are characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that with TMAH concentration increases, the roughness of bottom surface will decrease. The addition of IPA into TMAH solution improves the morphology of the bottom surface significantly. Low temperature is beneficial to get a smooth bottom surface. Furthermore, etching time can change the bottom surface roughness. A model is proposed to explain the etching processes. The hillock area ratio of the bottom surface has the same tendency as the etching area ratio. Finally, smooth silicon inverted trapezoidal patterns are obtained for epitaxial growth of GaN-based light emitting diode (LED) devices.

High-quality fiber fabrication in buffered hydrofluoric acid solution with ultrasonic agitation

An etching method for preparing high-quality fiber-optic sensors using a buffered etchant with ultrasonic agitation is proposed. The effects of etching conditions on the etch rate and surface morphology of the etched fibers are investigated. The effect of surface roughness is discussed on the fibers' optical properties. Linear etching behavior and a smooth fiber surface can be repeatedly obtained by adjusting the ultrasonic power and etchant pH. The fibers' spectral quality is improved as the ratio of the pit depth to size decreases, and the fibers with smooth surfaces are more sensitive to a bacterial suspension than those with rough surfaces.

Effect of etching conditions on the formation of a regular porous structure of A3B5 semiconductors

In this paper, the basic factors affecting the formation of porous structure of A3B5 semiconductors were ascertained. These factors are important from the standpoint of controlling the parameters of porous structures. The morphology of porous structures was studied using scanning electron microscope JSM-6490. The chemical composition was studied using the method of EDAX, diffractometric studies were carried out using the diffractometer DRON-3M

Effect of etching conditions on pore shape in etched ion-track polycarbonate membranes

We have undertaken a systematic investigation of the influence of methanol and applied transmembrane potential on the shape of conical pores produced by the track-etch technique. Heavy ion tracks in polycarbonate foils were chemically etched in an electrolytical cell under various conditions (different methanol content in the etchant, and applied potentials). It is found that the cone angle of the conical nanopore is dependent on the amount of methanol present in an alkaline etching solution as well as on the applied transmembrane potential. A combination of both these techniques is proposed to obtain conical nanopore with more exaggerated base opening. Controlling these conditions provide a route to fabricate controlled shape pores in polycarbonate membranes that have potential applications in a wide array of fields.

Preparation of Large-Area Uniform Silicon Nanowires Arrays through Metal-Assisted Chemical Etching

A facile fabricating method has been established for large-area uniform silicon nanowires arrays. All silicon nanowires obtained were single crystals and epitaxial on the substrate. Six kinds of silicon wafers with different types, surface orientations, and doping levels were utilized as starting materials. With the catalysis of silver nanoparticles, room-temperature mild chemical etching was conducted in aqueous solution of hydrofluoric acid (HF) and hydrogen peroxide (H2O2). The corresponding silicon nanowires arrays with different morphologies were obtained. The silicon nanowires possess the same type and same doping level of the starting wafer. All nanowires on the substrate have the same orientation. For instance, both (100)- and (111)-oriented p-type wafers produced silicon nanowires in the (100) direction. For every kind of silicon wafer, the effect of etching conditions, such as components of etchant, temperature, and time, were systemically investigated. This is an appropriate method to produce a large amount of silicon nanowires with defined type, doping level, and growth direction for industrial applications.

Computer program TRACK_TEST for calculating parameters and plotting profiles for etch pits in nuclear track materials

Computer program TRACK_TEST for calculating parameters and plotting profiles for etch pits in nuclear track materials

Effects of etching conditions on interface-treated trilayer junctions

The effects of an etching condition on the trilayer junctions fabricated by the interface treatment have been studied. The junctions have no deposited barriers and are made through an etching process and an annealing process at the surface of YBa 2Cu 3O 7− x (YBCO) films. We controlled the incidence angle of the ion beam in the etching process. The atomic-force microscope observations of the YBCO surfaces etched with different incidence angles suggested that the incidence angle affects the formation of amorphous layer. Moreover, it was found that the critical current of the junctions changed by the incidence angle. These results indicate that we can control the junction parameters of the interface-treated trilayer junctions.

Effect of dry etching conditions on surface morphology and optical properties of GaN films in chlorine-based inductively coupled plasmas

Dry etching of undoped, n- and p-type GaN films has been carried out in a planar type inductively coupled plasma (ICP) system. The effect of etching conditions on surface morphology and optical properties of GaN films etched in Cl2/Ar discharges was studied. All the GaN films showed overall similar etching behavior at 700 W ICP, 150 W rf, 40 mTorr, and 25% Cl2. The surface roughness was relatively independent of the rf power up to 150 W, resulting in quite smooth morphology (root-mean-square roughness 1.1–1.3 nm), while etching at higher chuck powers (>200 W) produced rougher surfaces due to increased ion bombardment. The lattice disorder and point defect density were lower during the ICP etching compared with reactive ion etching. The intensity of the band edge peak of as-grown n-GaN was decreased after the ICP etching, and the extent of intensity decrease was inversely proportional to the applied chuck power. By contrast, the as-grown p-GaN showed a weak intensity of band edge emission, but the peak shifted to 460 nm after ICP etching with substantial increase in photoluminescence intensity.

Fabrication and characterisation of dry etched [formula omitted] quantum dots

This paper reports the fabrication and optical properties of a series of quantum dots of ∼ 30–130 nm diameter dry etched from three different CdTeCdMnTe quantum wells. The effects of etching conditions on the physical profile and optical properties of the dots were investigated. Both strain relaxation and quasi-parabolic lateral quantum confinement were observed in the dots.

CH4 :H2 :Ar rf/ECR Plasma Etching of GaAs and InP

ABSTRACTA comparative study of CH4 :H2 , and CH4 :H2 :Ar rf-plasma and microwave electron cyclotron resonance (ECR) plasma etching of GaAs and InP is presented. The study is in two parts;(i) Kinetic studies of GaAs and InP etch rates as a function of the constituent gas flow rates, applied rf and microwave powers, substrate temperature and position. The results indicate that CH4 :H2 :Ar ECR etching of GaAs is 10× more efficient in the utilisation of the CH4 precursor gas than rf-plasmas. However, the absolute etch rates are lower (70 nm min−1 for rf and 25 nm min−1 for rf biassed ECR-plasmas).The effect of etching conditions on InP morphology is also examined.(ii) The study of electrical “damage” in GaAs/AlGaAs high electron mobility transistor (HEMT) Hall bar structures, was investigated by ECR-plasma etching off the top GaAs capping layer. Results indicate that ECR-plasma etching with an rf-bias between 0V and −30V does not significantly effect the electrical characteristics of such devices at 300K, with some degredation at 1.2 K.

Effect of Etching Condition on the Energy Resolution

The effect of etching conditions on the energy resolution was studied. In the present work cellulose nitrate CN-85 films were used as Solid State Nuclear Track Detectors. There exists a relation between the etching condition and the energy resolution.

The effect of etching conditions on the response of LR115

Bulk etch rates and α-particle track etch rates in LR115 have been measured in NaOH solutions of various concentrations in the range 1N–6N, at 40°C, 50°C, 60°C and 70°C. Bulk etch rates show saturation with increasing normality, while the α-particle track etch rates are independent of etching temperature. Comparison of two batches shows marked differences, although the general pattern of behaviour is similar in both batches. Computed track profiles for α-particles allow prediction of critical angle of α-particles of any energy, for any etching condition, which is useful in predicting track detection efficiencies theoretically.

Effect of etching conditions on the bulk-etch rate and track-etching response of CA80-15 cellulose nitrate

The bulk etching behaviour of a cellulose nitrate plastic, CA80-15 ∗∗ ∗∗ Manufactured by Kodak-Pathé of France. , has been studied and the effect of varying the concentration and temperature of the etching solution (NaOH) examined. In contrast to other studies, saturation of the bulk-etch rate with normality has not been observed in the range of normalities used, viz. 2–12N, at etching temperatures of 40–70°C. The nature of the response curve ( V T versus d E/d x) of cellulose nitrate to heavy ions has also been examined a a funcrtion of the normality of the etching solution. A plateau in the response curve is obtained in all cases at d E/d x>5 MeV mg −1 cm 2; the onset of the plateau is reached at lower d E/d x values for high normality compared to those for low normality. The slope of the curve in the pre-plateau region is flatter for the higher normalities (∼10–12N). The plateau etch-rate rises with normality up to ∼6N, but then declines again. Normalities below 6N seem generally to lead to the most useful response for CA80-15. In particular, 2N NaOH seems to offer the most desirable response in the region 1<d E/d x<5 MeV mg −1 cm 2, while at very low d E/d x (<1 MeV mg −1 cm 2) e.g. for proton detection, 6N NaOH offers at the most useful response. Because of the saturation in the response curve, CA80-15 cannot be used to identify particles with d E/d x ≳ 5 MeV mg −1 cm 2 (in practice, Z ≳ 12 for E ≲ 10 MeV/nucleon). Interpretation of the observed behaviour of the plastic is briefly considered in the paper.