Influence Of Oxygen Plasma Treatment Research Articles

Influence of oxygen plasma treatment on structural and spectral changes in gold nanorods immobilized on indium tin oxide surfaces.

Oxygen plasma treatment is commonly used to sterilize gold nanoparticles by removing chemical contaminants from their surface while simultaneously inducing surface activation and functionalization of nanoparticles for biological, electrocatalytic, or electrochemical studies. In this study, we investigate the influence of oxygen plasma treatment on structural and localized surface plasmon resonance (LSPR) spectral changes of anisotropic gold nanorods (AuNRs) immobilized on an indium tin oxide (ITO) glass substrate. Unlike AuNRs deposited on a glass slide, no noticeable structural change or deformation of AuNRs on ITO was observed while increasing the oxygen plasma treatment time. This result indicates that ITO provides structural stability to AuNRs immobilized on its surface. Additionally, single-particle scattering spectra of AuNRs showed the broadening of LSPR linewidth within 60s of oxygen plasma treatment as a result of the plasmon energy loss contributed from plasmon damping to ITO due to the removal of capping material from the AuNR surface. Nevertheless, an increase in the surface charge on the AuNR surface was observed by narrowing the LSPR linewidth after 180s of plasma treatment. The electrochemical study of AuNRs immobilized on ITO electrodes revealed the surface activation and functionalization of AuNRs by increasing plasma treatment. Hence, in this study, a significant understanding of oxygen plasma treatment on AuNRs immobilized on ITO surfaces is provided.

Effects of Oxygen Injection Rates on a-IGZO Thin-film Transistors with Oxygen Plasma Treatment

In this study, investigate the influence of oxygen plasma treatment on the oxide channel layer of amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors based on the amount of oxygen gas injected. The a-IGZO channel layer thin-film transistors (TFTs) were fabricated with plasma treatment of zero, three, six, or nine standard cubic centimeters per minute (sccm) of oxygen gas injection into the a-IGZO channel layer using gun-type plasma cells from a molecular beam epitaxy system after the post-annealing process. In this experiment, oxygen plasma treatment on the a-IGZO channel layer improved the electrical and surface-area performance. Of all the treatment conditions, the a-IGZO channel layer TFT treated with plasma from an injection of 6 sccm of oxygen gas showed excellent transfer characteristics. They include saturation mobility of 14.4 cm²/Vs, a threshold voltage of 4.5 V, an on/off current ratio of 1.1 × 10<SUP>8</SUP>, and an inverse subthreshold slope of 0.7 V/dec. Surface morphology analyses confirmed that increases in the oxygen gas injection rate decreased. A dynamic inverter test was conducted by configuring the logic circuit for the a-IGZO channel layer TFT, which verified the possibility for future application of the backplane device in active-driven displays.

Influence of oxygen plasma treatment on structural and spectral changes in silica-coated gold nanorods studied using total internal reflection microscopy and spectroscopy.

This paper shows how oxygen plasma treatment affects the structural, localized surface plasmon resonance (LSPR) spectral, and spatial orientation changes in single gold nanorods coated with a mesoporous silica shell (AuNRs@SiO2) in comparison with bare AuNRs with the same aspect ratio (AR). Single AuNRs@SiO2 subjected to different plasma treatment times were characterized using scanning electron microscopy and total internal reflection scattering (TIRS) microscopy and spectroscopy. The AR of the single AuNRs without a silica shell was decreased by structural deformation, while their LSPR linewidth was increased with increasing plasma treatment time. In contrast, single AuNRs@SiO2 showed much higher structural and spectral stability due to the silica shell under the energetic plasma treatment. Furthermore, there was no noticeable variation in the three-dimensional (3D) orientations of single AuNR cores in the silica shell before and after the plasma treatment. The results support that no significant structural and spectral changes occur in single AuNRs@SiO2 and that the silica coating enhances the stability of AuNR cores against oxygen plasma treatment. Therefore, fundamental information on the relationship among plasma treatment time, structural change, LSPR damping, and defocused orientation patterns is provided at the single-particle level.

Influence of oxygen-plasma treatment on AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors with HfO2 by atomic layer deposition: leakage current and density of states reduction

The electrical properties of AlGaN/GaN MOSHFETs with HfO2 prepared by atomic layer deposition with and w/o oxygen-plasma treatment (further referred to as PHf-MOS and Hf-MOS) were investigated. The sub-threshold slope of the MOSHFETs (350 and 150 mV dec−1 for Hf-MOS and PHf-MOS, respectively) were lower than that for HFET (450 mV dec−1), which also correspond with lower leakage current of the MOSHFETs (∼10−8 A mm−1 at −9 V for PHf-MOS). In addition, the density of the interface states at the oxide/GaN-cap layer near the conduction band edge and mid-gap (∼5 × 1012 and 2 × 1011 cm−2 eV−1, respectively) after PHf-MOS was lower than that for Hf-MOS (∼3 × 1013 and 2 × 1012 cm−2 eV−1, respectively). From the x-ray photoemission spectroscopy analysis we observed a shift in the Auger Ga LMM peaks (0.6 eV) and an increase of the intensity area of the Ga–O bond in the Ga2p3 spectrum after the oxygen-plasma treatment, mainly because the GaN-cap layer was oxidized and Ga2O3 was formed.

Enhanced biocompatibility of TiO2 surfaces by highly reactive plasma

In the present study the biological response to various nanotopographic features after gaseous plasma treatment were studied. The usefulness of nanostructured surfaces for implantable materials has already been acknowledged, while less is known on the combined effect of nanostructured plasma modified surfaces. In the present work the influence of oxygen plasma treatment on nanostructured titanium oxide (TiO2) surfaces was studied. Characterization of the TiO2 surface chemical composition and morphological features was analyzed after plasma modification by x-ray photoelectron spectroscopy and by scanning electron microscopy while surface wettability was studied with measuring the water contact angle. Cell adhesion and morphology was assessed from images taken with scanning electron microscopy, whereas cell viability was measured with a calorimetric assay. The obtained results showed that oxygen plasma treatment of TiO2 nanotube surfaces significantly influences the adhesion and morphology of osteoblast-like cells in comparison to untreated nanostructured surfaces. Marked changes in surface composition of plasma treated surfaces were observed, as plasma treatment removed hydrocarbon contamination and removed fluorine impurities, which were present due to the electrochemical anodization process. However no differences in wettability of untreated and plasma treated surfaces were noticed. Treatment with oxygen plasma stimulated osteoblast-like cell adhesion and spreading on the nanostructured surface, suggesting the possible use of oxygen plasma surface treatment to enhance osteoblast-like cell response.

Characteristics of ITO films with oxygen plasma treatment for thin film solar cell applications

The influence of oxygen plasma treatment on the electro-optical and structural properties of indium-tin-oxide films deposited by radio frequency magnetron sputtering method were investigated. The films were exposed at different O2 plasma powers and for various durations by using the plasma enhanced chemical vapor deposition (PECVD) system. The resistivity of the ITO films was almost constant, regardless of the plasma treatment conditions. Although the optical transmittance of ITO films was little changed by the plasma power, the prolonged treatment slightly increased the transmittance. The work function of ITO film was changed from 4.67eV to 5.66eV at the plasma treatment conditions of 300W and 60min.

Characteristics of aluminum-doped zinc oxide films with oxygen plasma treatment for solar cell applications

The influence of oxygen plasma treatment on the electro-optical and structural properties of aluminum-doped zinc oixde (AZO) films fabricated by radio frequency (RF) magnetron sputtering method were investigated. The films were exposed to various oxygen (O2) plasma treatment conditions. The plasma was created in a plasma enhanced chemical vapor deposition method. The resistivity, optical tranmittance, and work function of AZO films fabricated by RF magnetron sputtering was 5.6×10−4Ω·cm, 80%, and 4.6, repectively. The resistivity, optical trasmittance, and work function of the AZO films that were post-treated by O2 plasma treatment showed 9.2×10−4Ω·cm, 82%, and 5.6, respectively. The resistivity, carrier concentration, and hall mobility properties of AZO films deteriorated with increasing O2 plasma treatment power and time, whereas the work function and optical transmittance properties improved.

Effect of plasma modification on the mechanical properties of carbon fiber/phenolphthalein polyaryletherketone composites

AbstractA study was carried out to investigate the effect of plasma modification on the mechanical properties of carbon fiber/phenolphthalein polyaryletherketone composites. The influence of oxygen plasma treatment on the surface properties of carbon fibers was investigated by X‐ray photoelectron spectroscopy and atomic force microscopy. The results indicated that oxygen plasma treatment was capable of increasing the concentrations of the oxygen‐containing groups of the carbon fiber surface as well as enhancing surface roughness. Both the chemical bonding and mechanical interlocking gave rise to an increase of the interlaminar shear strength of composite. Scanning electron microscope photographs showed that the destruction mode of composites was changed after the carbon fibers were treated by oxygen plasma. The results also indicated that the flexural properties of plasma‐treated carbon fiber composites were improved. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers

Tratamento da Superfície de Cateteres de Poliamida 11 por Plasma de Oxigênio

Polyamide 11, as well as the great majority of polymers used in the construction of minimally invasive devices for medical use, shows no significant interaction with polar liquids, which limits its use in some applications, since most of internal biological tissues have hydrophilic character (high affinity for water). In this study, an investigation was made of the influence of oxygen plasma treatment of polyamide 11 surface on the composition, roughness and hydrophilicity. Through the plasma treatment, the polymer characteristics were changed to promote adhesion of a hydrophilic polymer layer on its surface, increasing the hydrophilicity and, consequently, the biocompatility of the polymeric device. Polyamide 11 catheters were submitted to different times of exposure to plasma, generated in an oxygen atmosphere with pressure, temperature and constant voltage. The treated and untreated (control) samples were then characterized using infrared spectroscopy, scanning electron microscope and contact angle measurements with water. Both the roughness and contact angle increased with the plasma treatment, indicating a possible improvement of the adherence of the hydrophilic layer coating the polymer.

Influence of Oxygen Plasma Treatment on Properties of Polyester Fabrics Coated with Copper Films

A lab radio frequency (RF) magnetron sputter coating system was used to deposit the nanoscale copper (Cu) films onto the surface of polyester plain fabric at room temperature. In this study,the polyester fabrics were treated under different duration with low temperature plasma.The effect of oxygen plasma pretreatment on surface morphologies,antistatic properties,mechanical properties of the copper-coated polyester fabrics is investigated. The surface morphology of modified polyester fabrics was characterized by atomic force microscopy (AFM).The AFM observations revealled the obvious corrasion was formed on the fiber surface,the sputtered copper particles were hard to cluster and uniformly distributed on the fiber surface with longer duration of plasma treatment.The antistatic properties of the copper-coated polyester fabrics was greatly improved after the oxygen plasma treatment.The hydrophobic behavior of the coated samples was also significantly improved .

Immobilization of protein streptavidin to the surface of PMMA polymer

Immobilization of the protein streptavidin to the surface of polymethyl methacrylate (PMMA) polymer was studied by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Different protocols were used to attach streptavidin to the PMMA surface: physical adsorption and chemical coupling. The influence of oxygen plasma treatment on the efficiency of streptavidin binding was studied. The presence of streptavidin coating on the PMMA surface was demonstrated by the appearance of N1s signal in the XPS spectra of coated PMMA samples. The XPS results have shown that oxygen plasma treatment improves binding of streptavidin to the PMMA surface. XPS results also showed that chemical coupling is more efficient than physical adsorption. In the case of physical adsorption, rinsing of the sample with water caused noticeable decrease of nitrogen concentration, while in the case of chemical coupling the nitrogen concentration was stable. AFM measurements showed that after deposition of streptavidin coating the originally smooth surface changed to dendrite structure.

Influence of oxygen plasma treatment on properties of Methyl-BCN film

Methyl-BCN film as a low dielectric material has been investigated by our group for Cu/low-k interconnection. We studied the ashing characteristics of Methyl-BCN films using oxygen plasma. As a contrast, porous-SiOCH films were also treated by oxygen plasma with the same conditions. The change of composition ratio of Methyl-BCN film is less than that of porous-SiOCH film after oxygen plasma treatment. There is no evident change in each bond of Methyl-BCN film after treatment, either. FT-IR analysis was carried out to investigate the chemical bonds of Methyl-BCN films and porous-SiOCH films with and without oxygen plasma treatment. The methyl groups of Methyl-BCN film were more stable than that of porous-SiOCH film.

Influence of oxygen plasma treatment on interfacial properties of poly(p‐phenylene benzobisoxazole) fiber‐reinforced poly(phthalazinone ether sulfone ketone) composite

AbstractThe influence of oxygen plasma treatment on both surface properties of poly(p‐phenylene benzobisoxazole) (PBO) fibers and interfacial properties of PBO fiber reinforced poly(phthalazinone ether sulfone ketone) (PPESK) composite were investigated. Surface chemical composition, surface roughness, and surface morphologies of PBO fibers were analyzed by X‐ray photoelectron spectroscopy (XPS), Atomic force microscopy (AFM), and scanning electron microscopy (SEM), respectively. Surface free energy of the fibers was characterized by dynamic contact angle analysis (DCAA). The interlaminar shear strength (ILSS) and water absorption of PBO fiber‐reinforced PPESK composite were measured. Fracture mechanisms of the composite were examined by SEM. The results indicated that oxygen plasma treatment significantly improved the interfacial adhesion of PBO fiber‐reinforced PPESK composite by introducing some polar or oxygen‐containing groups to PBO fiber surfaces and by fiber surface roughening. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Influence of oxygen plasma treatment on boron carbon nitride film composition

Variations in the composition and bonds of boron carbon nitride (BCN) film caused due to an oxygen (O2) plasma ashing process are investigated for a low dielectric constant (low-k) insulating film for next generation LSI devices. The O2 plasma treatment is preformed for BCN samples with various C compositions. The etching rate of BCN films with an O2 plasma decreases with increasing C composition. The reaction of O atoms is suppressed in the BCN film with a high C composition. B–N and B–C bonds with lower bond energies are easily broken by the O2 plasma and replaced by the generation of B–O, N–O, and C–O bonds. The B-atom concentration for all samples is decreased significantly by the O2 plasma treatment. Ion bombardment may play a more dominant role than the O-atom reaction in the etching of the BCN film. The existence of C–N bonds with a high bonding energy may suppress etching and incorporation of O atoms.

Application of interfacial fracture mechanics approach for obtaining design rules for flip chip interconnections

The reliability of an electronic package can be described by a physics-of-failure approach. Crack initiation and propagation in the bulk material and interface leads to catastrophic mechanical and finally to electrical failure. Therefore, bulk and interfacial fracture mechanics is a suitable method to describe the reliability of an electronic package. As package, a stud bump bonding flip chip interconnection on a thermoplastic substrate material [liquid crystal polymer (LCP)] is studied. The paper focuses on the description of the interfacial cracking between the underfill and the LCP. This is used to obtain design rules for flip chip interconnection on LCP by means of finite element analysis. Geometry design parameters—fillet shape, chip and substrate sizes—are studied. Moreover, the influence of material properties of the substrate and underfill are investigated. The impacts of the parameters are evaluated by analyzing the energy release rate (ERR) and mode-mixity in the interface. For determination of the critical ERR as function of the mode-mixity, a modified button shear test is utilized. The button, made out of underfill, is cured on the LCP substrate. A pre-delamination is established using a Teflon strip. The critical ERR for different mode-mixities is obtained by varying the shearing height of the button test. Additional, the influence of oxygen plasma treatment of the LCP substrate on the interfacial cracking is taken into account. In the investigation, design rules for increasing the reliability of flip chip interconnections are obtained. Moreover, a modified button-test is applied to obtain critical energy releases rates for different mode-mixities for the interface underfill/LCP. These results are used to optimize the geometry and materials of flip chip interconnections for automotive sensor applications in respect to delamination risk between substrate and underfill.

Influence of oxygen plasma treatment on properties of ZrO 2 films prepared by e-beam evaporation techniques

Zirconia films were prepared by e-beam evaporation, and oxygen plasma treatment was used to modify film properties. Spectrophotometry, x-ray diffractometry (XRD), and atomic force microscopy were used to characterize refractive index, extinction coefficient, microstructure, and surface roughness, respectively. The experimental results indicate that both refractive index and extinction coefficient of the films were reduced slightly after oxygen plasma treatment, with the decrease of intrinsic stress and surface roughness. From XRD spectra, the intensity decrease of the T(110) diffraction peak was clearly observed after the treatment, which was caused by the restructuring of the film atoms.

Surface analysis of oxygen plasma treated poly( p-phenylene benzobisoxazole) fibers

The influence of oxygen plasma treatment on surface properties of poly( p-phenylene benzobisoxazole) (PBO) fibers and aging effect of the oxygen plasma modified PBO fiber surfaces were investigated by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and dynamic contact angle analysis (DCAA), respectively. The results indicated that the oxygen plasma treatment introduced some polar groups to PBO fiber surfaces, enhanced surface roughness and changed surface morphologies of PBO fibers by plasma etching and oxidative reactions. Surface wettability of PBO fibers may be significantly improved by increasing surface free energy of the fibers via oxygen plasma treatment. Aging effect of the oxygen plasma treated PBO fibers showed that the fiber surface wettability degraded in the first several days after the plasma treatment, and it was found to be changeless as the aging time continued as long as 30 days.

Influence of Oxygen Plasma Treatment on Surface Properties of Armos Fiber

Armos fiber (F-12 aramid fiber in paper) was provided with broad application foreground as reinforcement material for advanced composites in aviation and spaceflight field, due to its outstanding properties, such as high modulus, high strength, high temperature resistance, erosion resistance and so on. However, the exertion of property was still limited by slippery surface, low surface energy and weak interfacial adhesion performance. In this study, the effects of oxygen plasma treatment time on polar functional groups introduced onto the fiber surface, surface free energy and surface topographic images were discussed by X-ray photoelectron spectroscopy (XPS) analysis, dynamic contact angle analysis system (DCA) and atomic force microscopy (AFM), respectively. It was found that the content of oxygen element and polar functional groups on fiber surface were all increased obviously after oxygen plasma treatment. The content of oxygen element on surface for untreated F-12 aramid fiber was 11.13%, while it increased to 15.20% after oxygen plasma treatment for 10 min; The content of polar functional groups on surface for untreated F-12 aramid fiber was 28.14%, while it increased to 38.11% after oxygen plasma treatment for 10 min. The polar component (γp) of fiber surface energy increased sharply from 6.82 mN/m to 36.68 mN/m after 10 min plasma treatment, the total surface free energy was increased from 46.26 mN/m to 64.66 mN/m.The results indicated that oxygen plasma treatment had introduced a large amount of reactive functional groups onto the fiber surface, and these groups can form together as covalent bonding to improve the surface wettability and increase the surface energy of fibers. At the same time, oxygen plasma treatment was able to generate a mass of bulges and grooves on F-12 aramid fiber surface, which had an active effect on increasing the chemical bond and mechanical function between fiber and resin and enhancing the interfacial adhesion performance of composite. The fiber surface grooves had been increased with the time prolonging before 10 min while decreased after 10 min, the results maybe relate to partial organic on fiber surface melting. It had an adverse effect on the interfacial adhesion properties of composite. Therefore, the optimum plasma treatment time was between 5 min and 10 min.

Physical and electrical characteristics of Ba(Zr0.1Ti0.9)O3 thin films under oxygen plasma treatment for applications in nonvolatile memory devices

In this study, the effects of oxygen gas plasma treatment on the surface of Ba(Zr0.1Ti0.9)O3 (BZT) films are investigated. The influence of oxygen plasma treatment on the crystal structure is developed by X-ray diffraction patterns and on the electrical characteristics are measured by the Al/BZT/Pt capacitor (metal–dielectric–metal) structure. Experimental results show that the capacitance increases and the leakage current density decreases as the oxygen plasma is treated on the BZT films. These results clearly indicate that the electrical characteristics of BZT films have effectively improved by means of the oxygen plasma surface treatment process.

Influence of oxygen plasma treatment on hydrogen chloride removal of activated carbon fibers

The oxygen plasma treatment of activated carbon fibers (ACFs) was carried out to introduce oxygen-containing groups onto carbon surfaces. Surface properties of the ACFs were determined by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). N 2/77 K adsorption isotherms were investigated by BET and D–R plot methods to characterize specific surface area, pore volume, and pore size distribution. The efficiency of hydrochloride removal was confirmed by two kinds of methods; one is detecting tubes (range: 1–40 ppm), and the other is a gas chromatography technique. As experimental results, the hydrochloride removal efficiency of the ACFs was increased with the number of plasma treatment times up to around 300%, resulting from newly formed oxygen-containing functional groups (especially phenolic and carboxylic) on carbon surfaces, in the decreased specific surface areas or pore volumes. These results indicate that the plasma treatment leads to the increase of hydrochloride removal due to the improvement of surface functional groups containing oxygen on the carbon surfaces.