Radio Frequency Magnetron Sputtering Technique Research Articles

Angle-dependent AC susceptibility, low-field magnetoresistance and switching behaviour of La0.66Sr0.34MnO3/YSZ(001) films

The La0.66Sr0.34MnO3 (LSMO) films with thickness 200–330 nm have been grown at 750 °C on lattice-mismatched (001)-plane oriented yttria-stabilized zirconia (YSZ) using radio frequency magnetron sputtering technique. The films demonstrated columnar growth structure characterized by coexistance of grains with the averaged diameter of about 50 nm and well defined crystallographic orientations of a pseudocubic LSMO lattice, namely, (001)LSMO[110]//(001)YSZ[100] and (110)LSMO[110;100]//(100)YSZ[100]. Alternating current (AC) magnetic susceptibility, χ(H) ∼ dM/dH, and magnetoresistance, MR(H), of the films were measured at 78 and 295 K with DC magnetic field (H) applied either in-plane or out-of-plane. Unusually sharp peaks at H = ±HSW and clearly defined switching behaviour have been indicated at 78 K in both the χ(H) and MR(H) plots. The HSW values were found to increase with the out-of-plane angle, α, according to the relationship HSW = HSW0/cosα (HSW0 = 4.0 and 1.4 kA/m at 78 and 295 K, respectively) while negligible variation of HSW has been indicated by varying direction of H in a film plane. The investigations revealed close correlation between χ(H) and low-field magnetoresistance. The observed angle-dependent peak-like χ(H) anomalies have been explained assuming magnetization reversal of the multigrain films governed by interparticle interaction and pinning of magnetic domains at grain boundaries. Unusual pit-like anomaly of the transverse biased susceptibility (TS) indicated at H = ±HSW has been explained in a framework of the TS theory developed for isolated uniaxal ferromagnetic particles assuming coexistance of grains with several fixed easy axis orientations in a film plane.

Characterization of Cu2ZnSnS4 thin films prepared with and without thin Al2O3 barrier layer

We investigated the effect of thin Al2O3 barrier layer (∼20 nm) deposited by radio frequency magnetron sputtering technique on the structural, morphological, optical, and electrical properties of Cu2ZnSnS4 (CZTS) films. Major differences in the crystalline qualities of the films were not observed with the addition of the Al2O3 layer except for a small decrease in crystallite size. Raman spectra of the film with the Al2O3 layer exhibited the peaks belonging to ZnS and Cu2-xS secondary phases. X-ray photoelectron spectroscopy analysis showed that SO42- and CuSO4 compounds were formed on the surfaces of the films. The formation of the CuSO4 phase was associated with the bonding between CuO and S in an oxidized CZTS surface. The presence of the ZnS, Cu2-xS secondary phases, and CuSO4 on the surfaces of the films were also confirmed by scanning electron microscopy images. The film with the Al2O3 layer differed from the other films with its surface that have randomly distributed porous-structured agglomerations and a decrease in the ZnS secondary phases on its surface. All films exhibited different Na distributions in secondary ion mass spectroscopy depth profiles. The Al2O3 layer caused a slower gradient in Na diffusion with decreasing the accumulation of Na element at a distinct region. The activation energy for the thermally activated band conduction was calculated as 0.030 eV and attributed to the thermal release of the holes from the vacancy of copper (VCu) defect states. The results of temperature-dependent conductivity measurements indicated that there were different conduction mechanisms in the films.

Preparation and Characterization of Radio Frequency Sputtered Delafossite p-type Copper Gallium Oxide (p-CuGaO2) Thin Films

In this research, CuGaO2 thin films were prepared on quartz substrates by radio frequency magnetron sputtering technique at 400 °C followed by subsequent annealing in N2 ambiance. The effects of annealing temperature on structural, morphological, optical, and electrical properties of CuGaO2 thin films are reported in this work. X-ray Diffraction (XRD) analysis confirmed the presence of single-phase CuGaO2 in the film annealed at 900 °C. Near stoichiometric composition ratio of Cu:Ga (1:1.08) was identified in the film annealed at 900 °C. The Field Emission Scanning Electron Microscope (FESEM) images showed an increase in the grain size with an increase in annealing temperature. A UV–V is spectrophotometer was used to perform optical studies in the 200–800 nm wavelength region on all films. The optical bandgap was calculated from the transmission studies and was found to be in the range of 2.77 to 3.43 eV. The films annealed at temperatures 800 °C and above were found to be p-type. The lowest resistivity value of 230 Ω-cm was achieved in the film annealed at 900 °C.

Structural properties and sensing performance of TaOx/Ta stacked sensing films for extended-gate field-effect transistor pH sensors

In this article, the TaOx/Ta stacked sensing films as sensing membranes were deposited onto n+-type Si substrate by a radio-frequency (RF) magnetron sputtering technique for solid-state extended-gate field-effect transistor (EGFET) pH sensors. The effect of rapid thermal annealing (RTA) treatment (300–700 °C) on structural properties of the TaOx/Ta stacked sensing films was investigated in detail. The chemical compositions, element profiles, crystallographic structures, surface morphologies, and film microstructures of the TaOx/Ta stacked sensing films were characterized by X-ray photoelectron spectroscopy, Auger electron spectroscopy, X-ray diffraction, atomic force microscopy, and transmission electron microscopy, respectively. The sensing performance of the TaOx/Ta stacked sensing films is most closely correlated with their relative structural features. Among these RTA temperatures, the best sensing performance including pH sensitivity, hysteresis and drift was achieved at the RTA temperature of 500 °C. The obtained experimental results showed that the TaOx/Ta stacked sensing film is considered a feasible alternative for pH sensor and biosensor applications.

Transport properties and crystallization of Li–Nb–O system on silicon

The present work is focused on the investigation of transport properties of LiNbO3 films synthesized through the crystallization of amorphous coatings as an alternative approach of high-quality films formation. Li–Nb–O amorphous films were deposited onto SiO2–Si substrates by the radio-frequency magnetron sputtering (RFMS) technique in an Ar environment. As-grown films crystallize under thermal annealing (TA) at the temperature of up to 600 °C with a formation of LiNbO3. The Hall effect analysis revealed that electrons are the major carriers in as-grown amorphous films, with the small-polaron hopping as a prime charge transport mechanism. TA in air provokes the increase in the carrier concentration from 6·1011 cm-3 to 6·1014 cm-3, originated from the NbLi antisite defect generation due to Li2O loss. We detected two concurrent transport processes contributing the net Hall mobility: the grain boundary limited and the bulk single-crystal limited mobility. Our results suggest that during the crystallization process, grain boundaries start playing a dominant role in charge transport, whereas when the grains get larger under recrystallization, the bulk single-crystal mobility prevails. The activation energy of the Hall mobility (Eaμ) and conductivity (Eaσ) has been determined for the studied films after TA at various temperatures. Eaμ rises non-monotonically from 0.1 eV with the annealing temperature and reaches a peak of 0.61 eV at a temperature of about 550 °C, which correlates with the trap concentration in LN films after TA. Besides, as followed from our analysis, the Nb4+ defects (electronic traps) are generated at the grain boundaries under TA and after recrystallization the intergranular barriers with the height of 0.5 eV limit the charge transport processes.

Determination of the interface band alignment of Mg2Si/4H‐SiC heterojuction for potential photodetector application

The Mg2Si/4H‐SiC heterojunction was prepared by radio frequency (RF) magnetron sputtering technique. The binding energies of Mg 2p, Si 2p, and C 1s core levels and the maxima of valence band were measured by X‐ray photoelectron spectroscopy (XPS). Using the optical bandgap of Mg2Si (0.78 eV) and 4H‐SiC (3.25 eV), the band offsets of valence band (VBO) and conduction band (CBO) at Mg2Si/4H‐SiC interface were identified as 1.47 and 1.00 eV, respectively. The band alignment was evaluated to be type‐I band alignment. The Mg2Si/4H‐SiC heterojunction could be a promising candidate for the infrared (IR) photodetector.

Comparative studies on the morphological, structural and optical properties of NiO thin films grown by vacuum and non-vacuum deposition techniques

The structural and optical characteristics of Nickel oxide thin films (NiOTF) formed on the soda-lime glass substrate (SLG) under vacuum and non-vacuum conditions are investigated in this work. The difference between RFMS (Radio Frequency Magnetron Sputtering; vacuum) and SP (spray pyrolysis; non-vacuum) was helpful in the development of NiOTF. Deposited films data for this study were characterized by using x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), scanning probe microscopy (SPM), and optical spectrophotometer. Structural studies disclosed that NiOTF developed via RFMS technique was more uniform with large crystals and lower surface roughness in contrast to that of developed via SP technique. Transmittance spectrum divulged that the transmittance of spray pyrolyzed NiO films are ∼10% less than that of ones produced by RFMS. Urbach energy analysis of NiOTF developed by RFMS and SP affirmed the findings of structural studies.

Investigation into the effect of substrate material on microstructure and optical properties of thin films deposited via magnetron sputtering technique

This study aims at investigating the effect of the substrate material on growth mechanism and also microstructure of Ta2O5 thin films. For this purpose, atomic force microscopy, scanning electron microscopy, and interferometry analyses were implemented to reveal the influence of silicon wafer and amorphous BK7 glass substrates on the nucleation and growth mechanisms of Ta2O5 thin films deposited via the radio frequency magnetron sputtering technique. Results indicated that those films with finer morphologies had relatively higher nucleation densities. Compared with BK7 glass substrate, crystals formed on the silicon wafer were shown to be finer and had lower mean areas in more nucleation sites. Moreover, optical properties and morphological characteristics of the films on the silicon substrates had much more endurance after the annealing treatment. It was observed that shift in the transmission spectra of the deposited films after the treatment was insignificant, implying high packing density of the films. However, a 6-nm shift in the transmission spectra indicated low density and high porosity of the films. Finally, atomic force microscopy analysis along with the light scattering measurements confirmed the formation of a low-roughness film on the silicon wafer substrates.

On the origin of better hemocompatibility of the BCxNyOz coatings

The development of hemocompatible coatings on metallic implants is one of the challenges for blood-contacting implantable devices. In this paper, we investigated the blood-material interaction of BCxNyOz coatings deposited on Ti-6Al-4V substrates, using reactive radiofrequency magnetron sputtering technique with variation in nitrogen (N2) flow rate. A series of experiments, including hemolysis tests, erythrocytes, and platelets adhesion and activation analysis, dynamic blood coagulation, and plasma recalcification time tests, were performed to understand the blood-material interactions, qualitatively and quantitatively. The results revealed that the degree of hemolysis on all the samples was below 2.5%, suggesting their favourable interaction with RBCs. The interactions between erythrocytes and platelets with all the BCxNyOz coatings were reduced significantly compared to Ti-6Al-4V. BCxNyOz coatings could substantially delay the time of blood coagulation to the period of 60 min. The plasma recalcification time of coatings was also increased significantly. An effort has been made to rationalize the difference in hardness or blood compatibility parameters in terms of [N]/[B] or [N]/[C] ratio. The present study conclusively establishes that BCxNyOz coatings can significantly enhance hemocompatibility, thereby opening up a myriad of biomedical applications.

Surface Engineering Strategies to Enhance the In Situ Performance of Medical Devices Including Atomic Scale Engineering.

Decades of intense scientific research investigations clearly suggest that only a subset of a large number of metals, ceramics, polymers, composites, and nanomaterials are suitable as biomaterials for a growing number of biomedical devices and biomedical uses. However, biomaterials are prone to microbial infection due to Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis), hepatitis, tuberculosis, human immunodeficiency virus (HIV), and many more. Hence, a range of surface engineering strategies are devised in order to achieve desired biocompatibility and antimicrobial performance in situ. Surface engineering strategies are a group of techniques that alter or modify the surface properties of the material in order to obtain a product with desired functionalities. There are two categories of surface engineering methods: conventional surface engineering methods (such as coating, bioactive coating, plasma spray coating, hydrothermal, lithography, shot peening, and electrophoretic deposition) and emerging surface engineering methods (laser treatment, robot laser treatment, electrospinning, electrospray, additive manufacturing, and radio frequency magnetron sputtering technique). Atomic-scale engineering, such as chemical vapor deposition, atomic layer etching, plasma immersion ion deposition, and atomic layer deposition, is a subsection of emerging technology that has demonstrated improved control and flexibility at finer length scales than compared to the conventional methods. With the advancements in technologies and the demand for even better control of biomaterial surfaces, research efforts in recent years are aimed at the atomic scale and molecular scale while incorporating functional agents in order to elicit optimal in situ performance. The functional agents include synthetic materials (monolithic ZnO, quaternary ammonium salts, silver nano-clusters, titanium dioxide, and graphene) and natural materials (chitosan, totarol, botanical extracts, and nisin). This review highlights the various strategies of surface engineering of biomaterial including their functional mechanism, applications, and shortcomings. Additionally, this review article emphasizes atomic scale engineering of biomaterials for fabricating antimicrobial biomaterials and explores their challenges.

Growth Optimization and Study on Structural, Morphological, Optical and Electrical Properties of As-Deposited Zinc Sulfide Thin Films Fabricated by Radio-Frequency Magnetron Sputtering Technique at Room Temperature

The deposition of Zinc Sulfide (ZnS) thin films is optimized using a radio-frequency (RF) magnetron sputtering technique with variable RF power to minimize deposition steps and lower the fabrication costs. Room temperature as-deposited film growth optimization is conducted by studying their structural, morphological, optical, and electrical properties. The target power and deposition rate were related by a slope of 0.1648 and a linear correlation coefficient (R) of 0.9893. Only one significant peak for the films in the XRD pattern indicated that the films are of a single crystalline structure. All the deposited thin films exhibited a ZB structure. It is observed that the micro-strain ranged from 36.00x10-3 to 4.14x10-3, and that of dislocation density ranged from 6.68 to 0.08 Line/cm2. The optical energy band gaps of as-deposited ZnS films at different deposition power were found from 3.31 to 3.37 eV. The average transmittance percentage was increasing from 71.63% to 84.29%, above 400 nm wavelength. The films exhibited n-type conductivity with bulk carrier density in the order of 1012 cm-3. The carrier concentration and mobility ranged from 2.84x1011 to 3.98x1012 cm-3 and 1.06 to 27.68 cm2/Vs, respectively. The minimum and maximum resistivity of 1.01x104 and 2.52´105 Ω-cm were noted for the film deposited at 90 and 60W power, respectively.

Embedded Transdermal Alcohol Detection via a Finger Using SnO2 Gas Sensors.

In this paper, we report the fabrication and characterization of a portable transdermal alcohol sensing device via a human finger, using tin dioxide (SnO2) chemoresistive gas sensors. Compared to conventional detectors, this non-invasive technique allowed us the continuous monitoring of alcohol with low cost and simple fabrication process. The sensing layers used in this work were fabricated by using the reactive radio frequency (RF) magnetron sputtering technique. Their structure and morphology were investigated by means of X-ray spectroscopy (XRD) and scanning electron microscopy (SEM), respectively. The results indicated that the annealing time has an important impact on the sensor sensitivity. Before performing the transdermal measurements, the sensors were exposed to a wide range of ethanol concentrations and the results displayed good responses with high sensitivity, stability, and a rapid detection time. Moreover, against high relative humidity (50% and 70%), the sensors remained resistant by showing a slight change in their gas sensing performances. A volunteer (an adult researcher from our volunteer group) drank 50 mL of tequila in order to realize the transdermal alcohol monitoring. Fifteen minutes later, the volunteer’s skin started to evacuate alcohol and the sensor resistance began to decline. Simultaneously, breath alcohol measurements were attained using a DRAGER 6820 certified breathalyzer. The results demonstrated a clear correlation between the alcohol concentration in the blood, breath, and via perspiration, which validated the embedded transdermal alcohol device reported in this work.

Evolution of defects and charge carrier transport mechanism in fluorine-doped tin oxide thin films upon thermal treatment

Fluorine-doped tin oxide (FTO) thin films were prepared by a radio frequency magnetron sputtering technique. The defects and charge carrier transport behavior in FTO thin films were evaluated during the transition process from amorphous to nanocrystalline structures. The stable lattice structure in FTO thin films was obtained as the annealing temperature reached 400 °C. Positron annihilation results indicated that defect evolution in the FTO thin films was shown in two stages, formation and reduction of vacancies/vacancy clusters. The carrier mobility of the FTO thin films annealed at 600 °C was enhanced twice the amount than that of the unannealed samples. The correlation between the results obtained from positron annihilation and the Hall effect revealed the importance of defect scattering in deciding the charge carrier mobility. A defect scattering mechanism was proposed to interpret the noticeable increment of carrier mobility in FTO thin films after thermal treatment.

Impact of Ar:O2 gas flow ratios on microstructure and optical characteristics of CeO2-doped ZnO thin films by magnetron sputtering

In this study, a radio frequency magnetron sputtering technique was applied to deposit eminently oriented ZnO thin films on stainless steel (SS316L). The effect of different ratios (Ar:O2) of gas flow ((20:0), (15:5), (10:10), (5:15), (0:20)) on optical and structural properties of CeO2-doped ZnO thin films has been examined. The increase in grain size of thin films was observed with a partial increase in the Ar:O2 sputtering gas at substrate temperature of 673 K. The average surface roughness of the thin films has increased with sputtering gas. The photoluminescence peak exhibited a broad green-yellow band spiked at 467 nm for all the samples of CeO2-doped ZnO thin films and a wide band of visible light focused in the 500–600 nm range. Intensity reduction of deep level emission peaks of ZnO films was observed. The refractive index of undoped and CeO2-doped ZnO thin films with various sputtering gas ratios (Ar:O2) were also investigated. The optimized argon gas flow rate findings allow us to choose the deposition conditions for CeO2-doped ZnO thin films for solar thermal applications.

Nanoscale domain imaging and the electromechanical response of zinc oxide nanorod arrays synthesized on different substrates

Zinc oxide nanorods (ZnO NRs) have gained considerable research interest due to their robust energy conversion efficiency. In the present work, ZnO NRs arrays were pinpointed to probe their electromechanical response under strain conditions. ZnO seed was sputtered on different substrates by radio frequency magnetron sputtering (RF) technique at 80 W constant power and 3.49 × 10−5 mbar base pressure. The X-ray diffraction patterns exhibit hexagonal wurtzite structure with preferred c-axis crystal directions in the (002) plane. The average thickness of the seed layer for all the samples was estimated at around 214.6 nm. Surface roughness and morphologies of the nanorods have been characterized by atomic force microscopy (AFM) and field emission scanning electron microscopy (FESEM), respectively. FE-SEM images show homogeneous growth in different directions on substrates. The average diameters of ZnO NRs on silicon, glass and ITO were 51, 58 and 61 nm, respectively. The average length of all the nanorods on the substrates were measured around 1–2 μm. The local piezoresponse measurements conducted on two selected domain regions of the nanorod arrays had been characterized by piezoresponse force microscopy (PFM) to confirm the switching-piezoelectric behavior.

Effects of sputtering parameters and annealing temperatures on magnetic properties of CoFeB films

In this paper, soft magnetic CoFeB films were successfully deposited onto silicon substrates using radio frequency (RF) magnetron sputtering technique and their morphology, roughness (Rq) and magnetic properties were focused. Before annealing, CoFeB films prepared with different sputtering powers (60 W, 90 W, 120 W and 150 W) exhibit amorphous structure. The out-of-plane coercivity (Hc) gradually enhances from 40.2 to 66.4 Oe as the sputtering power increases, and the saturation magnetization (Ms) reaches the maximum of 1117 emu/cm3 at 90 W sputtering power. Then, the CoFeB film samples with 90 W were annealed by 200 °C, 300 °C, 400 °C and 500 °C, respectively. Annealing treatments at 300 °C and 400 °C transfers amorphous state into crystalline state, which is demonstrated by the appearance of the observable diffraction peak of CoFe (110). The out-of-plane Hc decreases from 40.2 to 30.5 Oe at annealing temperature range of RT to 300 °C. The annealed film has a greatest Ms of 1280 emu/cm3 at 300 °C. However, the Hc gradually increases from 30.5 to 68.9 Oe annealed from 400 °C to 500 °C due to the deterioration of the thin film. Collectively, the process conditions of sputtering at 90 W and annealing at 300 °C or 400 °C are favorable for crystallization and excellent magnetic properties in CoFeB films.

Optical, electronic, and microstructural properties of mixed phase RF magnetron sputtered vanadium oxide thin films on quartz and aluminized quartz

Amorphous vanadium pentoxide (major phase) thin films of various thicknesses were grown on the substrates that possessed low (aluminized quartz) and high (quartz) infrared (IR) emittance property utilizing radio frequency (RF) magnetron sputtering technique. Microstructural characterizations are carried out by several techniques such as noncontact optical profilometry, energy dispersive X‐ray (EDX) spectroscopy, X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and X‐ray diffraction (XRD). The as‐grown amorphous films show stoichiometric vanadium oxide, where vanadium is in V5+ as a major proportion compared with V4+ states. Thermo‐optical properties, namely, solar transmittance (τs), reflectance (ρs), absorptance (αs) and IR emittance (εir) along with optical constant, for example, optical band gap, are evaluated. A modified Urbach equation was used to simulate the optical absorption data to understand the presence optical absorption below the band edge.

IMPROVEMENT IN STRUCTURAL, OPTICAL AND ELECTRICAL PROPERTIES OF ITO FILM THROUGH AlN AND HfO2BUFFER LAYERS

Indium Tin Oxide (ITO) films were deposited on glass substrate using radiofrequency (RF) magnetron sputtering technique. To improve the physical characteristics of the ITO film, AlN and HfO2buffer layers were deposited on glass prior to the film deposition. The ITO/glass, ITO/AlN/glass and ITO/HfO2/glass films were annealed using CO2laser and electrical oven heating methods. The crystallinity of the ITO film was improved due to the incorporation of AlN and HfO2buffer layers and also by the post-deposition annealing process. The optical transmittance of the ITO was also increased due to the presence of the buffer layers. Similarly, the annealed ITO films grown on buffer layers exhibited lower values of the sheet resistance as compared to the film deposited without buffer layers. The laser annealing technique was more found to be more effective in reducing the ITO sheet resistance.

Development of ZrB2-Based Single Layer Absorber Coating and Molten Salt Corrosion of Bulk ZrB2–SiC Ceramic for Concentrated Solar Power Application

This study has dual objectives, one to develop single layer ZrB2-SiC-based ceramic absorber coating on stainless substrate, and another aim is to explore the degradation of ZrB2- SiC bulk ceramic in molten solar salt. In particular, we report the molten salt corrosion behavior of earlier developed ZrB2-SiC ceramic composite at 400 °C for 100 h. The corrosion rate in solar salt was determined to be 0.73 ± 0.09 mg h-1/cm2by gravimetric analysis. Binary and ternary oxide phases were formed due to electrochemical corrosion. The hot-pressed bulk ZrB2-SiC ceramic exhibits a high solar absorptance of 0.848 and also a high thermal emissivity of 0.66. A one-layer solar selective absorber coating without antireflection layer was developed using the ceramic disk as a sputtering target. When deposited using radio frequency (RF) magnetron sputtering technique on stainless steel substrate, a solar absorptance of 0.769 and thermal emissivity of 0.15 was obtained for an amorphous coating of thickness ~90 nm, without antireflection coating. The composition, determined by electron probe microanalyzer and X-ray photoelectron spectroscopy techniques, revealed nonstoichiometric phases in the layer with a relatively higher concentration of the lighter elements. The implication of the present work for concentrated solar power application is discussed. © 2021 American Chemical Society. All rights reserved.

High Performance of IZO Coated on PET Substrate for Electroluminescence Device Using Oxygen Plasma Treatment

Thin films of indium zinc oxide (IZO) were deposited on polyethylene terephthalate (PET) substrate with varying plasma power (from 100 W to 300 W) using the radio-frequency (RF) magnetron sputtering technique and electroluminescence (EL) devices. The IZO films that were obtained from this process were treated with oxygen plasma powers using the plasma-enhanced chemical vapor deposition (PECVD) system. After this treatment, the microstructural, electrical, and optical properties of IZO films were observed and reported. The result showed that the IZO/PET films was fabricated at the lowest resistivity ( 2.83 × 10 − 3 Ω · cm ), while the optical characterization displayed the maximum transmittance of 95% in the visible region with a smooth morphology and good crystalline structured, affected by the 300 W of plasma power with the optimum carrier concentration ( 4.93 × 10 21 c m − 3 ) and hall mobility (42.12 cm2/V·sec), respectively. The luminance properties and the EL efficiency were also investigated and shown a 300 W highest point of plasma power with 84 cd/m2 and 0.924 lm/W. The film properties were found responsible for producing and improving the performance of IZO/PET substrate, suitable for displaying the devices.