Selective Deposition Method Research Articles

Highly textured AlN film synthesized on a graphene-like undercoating

Piezoelectric properties of polycrystalline AlN films are strongly dependent on the texture of the material. For a number of applications, such as microelectromechanical systems (MEMS) and acoustic resonators, it is important to have a well-defined (002) orientation of the crystallites. Using an original method of selective deposition of graphene-like films (GLFs) followed by a simple, safe and efficient chemical vapor deposition (CVD) of AlN, we clearly demonstrate that the GLF sublayer does enhance the texture quality of AlN columnar structures. The improved crystal orientation along the (002) direction for AlN film grown on GLFs is locally visualized using a scanning electron microscope (SEM) and quantitatively reinforced using Raman spectroscopy.

Routes towards manufacturing biodegradable electronics with polycaprolactone (PCL) via direct light writing and electroless plating

The electronic industry has room for improvement in adopting cleaner strategies, both in production processes (often energy-intensive and polluting) and in waste management. Many small components like security tags are routinely disposed of via general waste, which could be reduced adopting biodegradable polymers. In this work, a method for selective deposition of metallic micro-tracks on polycaprolactone (PCL) for circuitry integration is presented. The polymer is biodegradable, flexible, suitable for 3D printing, and can be obtained from sustainable sources. Photoreduction of Ag ions was used to generate seeds for subsequent selective electroless copper (Cu) plating in a process that avoids common but undesirable compounds such as cyanides and palladium. Two different photopatterning methods were successfully used to achieve selective Cu plating: flood exposure with a 460 nm light-emitting diode (LED) and direct laser writing (DLW) using a 405 nm laser, achieving 47 ± 11 μm wide tracks. The deposition of uniform Cu layers on PCL substrates is demonstrated, with thicknesses of up to 14 μm and electrical conductivities of up to 2.06 × 107 S m−1, which is near the conductivity of bulk Cu (5.89 × 107 S m−1). Cu-plated interconnects were demonstrated to be fully functional for powering a 5 SMD LEDs circuit. Furthermore, DLW enabled the interconnect manufacturing on an uneven substrate. This method is flexible, selective, low-cost, vacuum-free and of minimized environmental impact, and it provides a new route towards the manufacturing of biodegradable electronics.

Fabrication of TiO2 nanodot films using simple solution dipping method and block copolymer template

Block copolymer (BCP) self-assembled nanostructures as a template in conjunction with a low-cost inorganic material deposition method can be a practical solution for many applications in the fields of microelectronics, optoelectronics, and plasmonics. Here, we demonstrate the fabrication of TiO2 nanodot films using polystyrene-b-polymethylmethacrylate (PS-b-PMMA) BCP as a template and a simple solution dipping process for TiO2 deposition. For this purpose, we prepared BCP templates using two different methods, namely, the selective deposition method and the masked deposition method. In the selective deposition method, as-grown self-assembled cylinder forming PS-b-PMMA was used as a template and in the masked deposition method, PMMA was etched out selectively from PS-b-PMMA nanostructured films. The scanning electron microscopy results show the average diameter of TiO2 nanodots grown by the selective deposition method is smaller compared to the masked deposition method, whereas the inter-nanodot distance is similar for both deposition methods. X-ray diffraction and photoluminescence confirm the formation of TiO2 in samples deposited by these two methods. The smaller nanodot size for the selective deposition method can be attributed to the limited interaction of the Ti precursor used here with the PMMA copolymer active functional groups. Therefore, in addition to being advantageous due to less processing steps, the selective deposition method can be used for the fabrication of lower dimensional nanostructures by identifying proper precursors and polymers and by controlling the interaction parameters. Our results will be useful for exploring interactions of other polymers with inorganic material precursors and thereby fabricating different nanostructures with desired morphologies using a simple and cost-effective dipping method.

Preparation of Z-scheme Au-Ag2S/Bi2O3 composite by selective deposition method and its improved photocatalytic degradation and reduction activity

In this work, Z-scheme Ag2S/Bi2O3 composites were fabricated through the precipitation of Ag2S nanoplates on the surface of Bi2O3 microrods. Consequently, Au nanoparticles were selectively deposited on the Ag2S nanoplates surface to obtain.Au-Ag2S/Bi2O3 composites using near-infrared light photodeposition method. The characterization results indicate that the Ag2S nanoplates were uniformly anchored on Bi2O3 surface, and Au nanoparticles were highly dispersed on the surface of Ag2S nanoplate instead of Bi2O3. Acid orange 7 (AO7), Rhodamine B (RhB) and Cr(VI) were chosen as model reactant for the evaluation of photocatalytic degradation and reduction activity of the products under simulated sunlight irradiation. After the decoration of Ag2S nanoplates, the photocatalytic activity of Ag2S/Bi2O3 is much higher than that of bare Bi2O3, and the optimal catalytic efficiency is achieved by 12 %Ag2S/Bi2O3 sample. More importantly, the photocatalytic activity of 12 %Ag2S/Bi2O3 sample can be further enhanced by the selective decoration Au nanoparticles on the Ag2S nanoplates. Among the ternary composites, 2Au-12 %Ag2S/Bi2O3 sample with the Au content of 2% exhibits highest catalytic efficiency for 60 min (AO7: 96%; RhB: 56%; Cr(VI): 65%). The possible mechanism for the improvement of the photocatalytic activity of Bi2O3 by Ag2S and Au decoration was proposed.

Reinforcement of material extrusion 3D printed polycarbonate using continuous carbon fiber

Additive manufacturing (AM) technologies are capable of fabricating custom parts with complex geometrical shapes in a short period of time relative to traditional fabrication processes that require expensive tooling and several post processing steps. Material extrusion AM, known commercially as Fused Filament Fabrication (FFF) technology, is a widely used polymer AM process, however, the effects of inherent porosity on mechanical strength continues to be researched to identify strength improvement solutions. To address the effect of porosity and layer adhesion on mechanical properties (which can sometimes result in 27–35% lower ultimate tensile strength when compared to plastic injection molding), an approach was employed to reinforce 3D printed polycarbonate (PC) parts with continuous carbon fiber (CF) bundles. ASTM D638 Type I specimens were fabricated with printing interruptions to manually place and embed CF bundles. Specimens contained either one, two, or three layers of embedded CF bundles. Results demonstrated a maximum of 77% increase in tensile yield strength when PC was reinforced with three CF bundles and micrographs showed multiple regions with zero porosity due to the CF inclusion. PC with three bundles of CF (modulus of 3.36 GPa) showed 85% higher modulus of elasticity than the neat PC specimens (modulus of 1.82 GPa). The manual placement of CF and its impact on mechanical properties motivated the development of an automated selective deposition method using an ultrasonic embedding apparatus. Substantial technology development towards the embedding process of continuous carbon fiber bundles using ultrasonic energy was achieved in an automated fashion which is complementary of digital manufacturing and novel when compared to other existing processes.

Shape control and selective decoration of Zn2SnO4 nanostructures on 1D nanowires: Boosting chemical–sensing performances

One–dimensional (1D) heterostructures are promising for the fascinating physical/chemical properties. However, the selective deposition of innovative materials as efficient active sites on the backbone material is still challenging and meaningful. Herein, a universal strategy is presented to synthesize the novel 1D heterostructure, which is constituted of Mn3O4 nanowires (Mn3O4 NWs) and nano–sized Zn2SnO4 subunits with controllable morphologies including Zn2SnO4 nanorods (Zn2SnO4 NRs), Zn2SnO4 nanocubes (Zn2SnO4 NCs) and Zn2SnO4 nanooctahedrons (Zn2SnO4 NOs). The 1D Mn3O4/Zn2SnO4 heterostructure is proved to generate abundant surface adsorbed oxygen molecules to modulate the sensing activity in chemical sensors (CSs) for application in the acetone vapor detection. The developed gas sensor shows enhanced responses, ultrafast response time and great stability. The selective deposition method and interface engineering will open up an avenue to design the heterostructured nanomaterials for high–performance CSs and other potential applications.

Area selective deposition of TiO2 by intercalation of plasma etching cycles in PEALD process: A bottom up approach for the simplification of 3D integration scheme

A selective deposition process for bottom-up approach was developed in a modified plasma enhanced atomic layer deposition (PEALD) sequence. As a case study, a very standard PEALD TiO2 using organo-amine precursor and O2 plasma is chosen. The metal oxide selectivity is obtained on TiN versus Si-based surfaces by adding one etching/passivation plasma step of fluorine every n cycles in a PEALD-TiO2 process. Fluorine gas NF3 allows (1) to etch the TiO2 layer on Si, SiO2, or SiN surface while keeping few nanometers of TiO2 on the TiN substrate and (2) to increase the incubation time on the Si-based surface. Quasi-in situ XPS measurements were used to study the incubation time between Si/SiO2 substrates versus TiN substrate. Results show that Si–F bonds are formed on Si and lock the surface reactions. The effectiveness of this atomic layer selective deposition method was successfully tested on a 3D patterned substrate with the metal oxide deposited only at the edge of metal lines.

Silver-mediated temperature-controlled selective deposition of Pt on hexoctahedral Au nanoparticles and the high performance of Au@AgPt NPs in catalysis and SERS.

Nanomaterials with high catalytic activity and good SERS properties can be used for sensitive and real-time in situ tracking of a catalytic process via SERS, which can be a powerful tool for investigating the products and mechanisms of the catalytic reaction. In the present work, Au@AgPt NPs with a {431}-faceted hexoctahedral Au core and an AgPt alloy shell exhibiting enhanced catalysis and good SERS activity were prepared by a facile silver-mediated temperature-controlled selective deposition of Pt. The complex hexoctahedral Au nanoparticles were synthesized first as nano-templates, followed by coating with a thin layer of Ag. Then, a temperature-controlled synthesis method for preferably depositing Pt on the hexoctahedral Au NPs was proposed to prepare Au@AgPt NPs. With the increase of the synthesis temperature, the Pt atoms were controlled to selectively deposit on the tips, edges or the entire surface of the nano-templates. By systematically investigating the effects of temperature, precursor consumption and synthesis time on the morphology, composition, optical properties, catalysis and SERS properties of the Au@AgPt NPs, the kinetic and thermodynamic mechanisms of the deposition of Pt on hexoctahedral Au nanoparticles were explored. The performance of the Au@AgPt NPs in SERS-based real-time in situ monitoring of the catalytic reaction was also investigated and verified. Besides, it is easy to regulate and control their SERS and catalytic performances through the selective deposition of Pt, according to the demand of the catalytic reaction and SERS monitoring. This work not only presents a new Au@AgPt nanostructure with good catalytic and SERS properties, but also develops a facile, universal and controllable method for selective deposition of Pt on Au nano-templates with a variety of morphologies.

Ag-Modified BiOCl Single-Crystal Nanosheets: Dependence of Photocatalytic Performance on the Region-Selective Deposition of Ag Nanoparticles

For single-crystal photocatalysts, selective deposition of noble metals as electron cocatalysts has been demonstrated to be an effective method to improve their photocatalytic performance. However, the effect of the selective deposition location of noble metals on the photocatalytic performance of single-crystal photocatalysts has not been really revealed, because the noble metals can only be selectively deposited on the electron-enrichment facets and cannot be modified on the hole-enrichment facets due to the absence of effective deposition methods. In this study, a photosensitization-deposition strategy, as a new selective deposition method, has been developed to selectively deposit Ag nanoparticles on the hole-enrichment regions (the lateral surfaces) of BiOCl single-crystal nanosheets (referred to as Ag/BiOCl(Dye)), and the effect of selective-deposition locations of Ag nanoparticles on the photocatalytic performance of BiOCl single-crystal photocatalysts has been investigated. For comparison, Ag nano...

Ion-Selective Deposition of Manganese Sulphate Solution from Trenggalek Manganese Ore by Active Carbon and Sodium Hydroxide

One of the step in manganese dioxide manufacturing process for battery industry is a purification process of lithium manganese sulphate solution. The elimination of impurities such as iron removal is important in hydrometallurgical processes. Therefore, this paper present the purification results of manganese sulphate solution by removing impurities using a selective deposition method, namely activated carbon adsorption and NaOH. The experimental results showed that the optimum condition of adsorption process occurs on the addition of 5 g adsorbent and the addition of 10 ml NaOH 1 N, processing time of 30 minutes and the best is the activated carbon adsorption of Japan. Because the absolute requirement of the cathode material of lithium ion manganese are free of titanium then of local wood charcoal is good enough in terms of eliminating ions Ti is equal to 70.88%.

Selective deposition of polycrystalline diamond films using photolithography with addition of nanodiamonds as nucleation centers

A new method of selective deposition of polycrystalline diamond has been developed and studied. The diamond coatings with a complex, predetermined geometry and resolution up to 5 μm were obtained. A high density of polycrystallites in the coating area was reached (up to 32·107 pcs/cm2). The uniformity of the film reached 100%, and the degree of the surface contamination by parasitic crystals did not exceed 2%. The technology was based on the application of the standard photolithography with an addition of nanodiamond suspension into the photoresist that provided the creation of the centers of further nucleation in the areas which require further overgrowth. The films were deposited onto monocrystalline silicon substrates using the method of “hot filaments” in the CVD reactor. The properties of the coating and the impact of the nanodiamond suspension concentration in the photoresist were also studied. The potential use of the given method includes a high resolution, technological efficiency, and low labor costs compared to the standard methods (laser treatment, chemical etching in aggressive environments,).

Preparation of Ru nanoparticles on TiO2using selective deposition method and their application to selective CO methanation

Selective CO methanation was investigated over Ru/TiO2 prepared using a selective deposition method with NaOH and NH3 aqueous solution as a pH adjuster. Control of pH by NH3 solution resulted in the small particle size of Ru (average 1.2 nm) and the formation of Na-free Ru/TiO2, leading to high CO methanation activity and a wide temperature window for selective CO methanation at low temperatures.

Performance of Low Resistivity Electrode Prepared by Electroless Plated for Amorphous Silicon Thin-Film Transistors

The TFTs array fabrication process for large-area TFT-LCD has been continuously developed for simplifying processing steps, improving performance and reducing cost in the process of mass production. In this study, the hydrogenated amorphous silicon (a-Si:H) TFTs with low resistivity electrodes , silver thin films, were prepared by using the selective deposition method that combined lift-off and electroless plated processes. This developed process can direct pattern the electrode of transistor devices without the etching process and provide ease processing steps. The as-deposited Ag films were annealed at 200 oC for 10 minutes under N2 atmosphere. The results shows that the adhesion properties can be enhanced and the resistivity has been improved from 6.0 μ,-cm, significantly decrease by 35%, of as-deposited Ag films by annealed. The thickness of Ag thin film is about 100 nm and the r. m. s roughness value is 1.54 nm. The a-Si:H TFT with Ag thin films as source and drain electrodes had a field effect mobility of 0.18 cm2/Vs, a threshold voltage of 2.65 V, and an on/off ratio of 3×104.

Liquid-phase Reductive Deposition as Novel Preparation Method for Highly Dispersive Nickel Catalysts

We have been developing the selective deposition method onto TiO2 nanoparticles, named as the liquid-phase selective-deposition method, where TiO2 plays a role of formation center of Ni nanoparticles as well as protection from the aggregative growth of the particles. The concept of this method is to well disperse and stabilize Ni nanoparticles on TiO2 surface by specific adsorption of Ni precursory complexes and then heterogeneous nucleation on the adsorption sites. The particle size was decreased with increasing the amount of Zn added, thus the catalytically active Ni surface area was increased. The selective deposition onto TiO2 surface and addition of Zn to the nanoparticle promoted the catalytic activity of Ni–Zn nanoparticle, e.g. the catalytic activity of Ni–Zn/TiO2 was ca. 10 times higher than that of the unsupported Ni nanoparticles. Ni in the nanocomposite was assigned as metallic, although their surface was oxidized under the atmospheric condition, but Zn and B were deposited as their oxide.

51.2: A. 4.3‐in. VGA (188 ppi) AMOLED Display with a New Driving Method

AbstractWe developed a 4.3‐inch VGA driver‐integrated AM‐OLED display with the world's highest pixel density of 188ppi by using high performance TFTs, a top emission structure, a technology for improving the precision of mask alignment in OLED deposition by RGB emitter's selective deposition method, and a 4Tr/Cell digital time‐gray‐scale driving method which improves image quality by fixing the gate potential of driving TFT.

A Method for Selective Deposition of Copper Nanoparticles on Silicon Surfaces

A one-step process for copper nanopatterning on a silicon surface is reported. The patterns were formed by selective copper electroless deposition from a diluted solution on defect sites on the silicon surfaces introduced by nanomechanical scratching. Field emission scanning electron microscopy and energy dispersive X-ray spectroscopy analyses show that copper particles were deposited preferentially on well-defined defect sites with high selectivity. The experiment demonstrated here shows a new one-step approach for metallic nanopatterning formation on a silicon surface. © 2003 The Electrochemical Society. All rights reserved.

An organic LED display exhibiting pure RGB colors

A full color 5.2-in. 1/4 video graphics array (VGA) passive-matrix organic light emitting diode (OLED) display has been developed. The display features 320 (×3)×240 pixels with an equivalent pixel size of 0.33×0.33 mm 2, white peak luminance of over 150 cd/m 2, and power consumption of 6 W. It uses a cathode patterning method with electrically insulated cathode separators and an RGB emitters selective deposition method with a high accuracy mask moving system. Furthermore, we have achieved pure RGB colors as well as high luminance from the cells by applying the optical interference effects. The display can display high resolution video rate pictures with virtually the same quality as a CRT can offer.

Organic LED full color passive-matrix display

A full color 5.2 in 1/4 VGA passive-matrix organic LED display has bee developed. The display has 320(×3)×240 pixels with an equivalent pixel size of 0.33×0.33 mm 2, white peak luminance of over 150 cd/m 2, and power consumption of 6 W. It uses a cathode patterning method with cathode separators and an RGB emitters selective deposition method by a high accuracy mask moving system. Passivation film for OLED has been also developed. It turned out that the EL characteristics remained almost identical and the dark spot growth were negligible for practical use after the storage tests.

REM-Untersuchungen zur quantitativen Metallographie von Karbiden in Schnellarbeitsstählen / SEM-Investigations into the Quantitative Metallographical Determination of Carbides in High Speed Steels

When examining carbides in high speed steels using the scanning electron microscope, the contrast obtained with the polished specimen in the unetched condition is often inadequate. High speed steels were examined, each of which contained two different types of carbides. With the MC-carbides present in the S 11-2-5-8 steel formed by powder metallurgical route, it was found that by reducing the accelerating voltage from the usual 15 kV down to 3 kV their contrast in the matrix was improved to such an extent that automatic quantitative image analysis became possible. The determination of M 2 C- and M 6 C-carbides in S 2-9-1-8 steel proved to be more difficult as, having the same back scattering coefficient, they both exhibited the same degree of contrast. A clear discrimination between these two carbides was however achieved chemically by element mapping. A difference in contrast, and thus reliable identification, was however also obtained by the more simple method of selective deposition, achieved using a Murakami etchant. Investigations in a scanning electron microscope equipped with a field emission cathode showed also that contrast reversal could be achieved at a voltage of 1 kV which affected only the M 2 C-carbides