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Rational concept for fully designing metal-oxynitride films through reactive gas-timing magnetron sputtering: A case study on zinc oxynitride film
(2025-08-10)
Khemasiri, Narathon
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Chananonnawathorn, Chanunthorn
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Horprathum, Mati
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Pornthreeraphat, Supanit
;
Saekow, Bunpot
Amorphous metal-oxynitride films—particularly zinc oxynitride (ZnON)—are emerging as promising materials for next-generation high-speed switching electronics, due to the absence of a potential barrier above the conduction band, unlike metal-doped ZnO. However, conventional reactive magnetron sputtering often face challenges in precisely controlling in an anion ratio, N/(N + O), because of the different reactivities of nitrogen and oxygen gases. In this work, we present a strategy to precisely control both the crystal structure and N/(N + O) ratio in ZnON films using a reactive gas-timing technique. By adjusting the oxygen gas-timing sequence (t<inf>O₂</inf>), we selectively induce different crystalline phases, which are closely related to the nitridation and oxidation of the sputtered Zn atom/cluster. This technique facilitates effective N incorporation into ZnO, enabling a broad range of N/(N + O) ratios from 0.048 to 0.964 and optical band gap variations from 1.49 eV to 3.22 eV. At an optimal t<inf>O₂</inf>, an amorphous phase is formed, attributed to a balanced nitridation and oxidation rate of the sputtered Zn atom/cluster that suppresses crystallization. The resultant amorphous ZnON film exhibits a high carrier mobility of 84.81 cm²/Vs, which is 1.16-fold and 35.89-fold greater than those of the cubic and hexagonal ZnON films, respectively. Our findings highlight the effectiveness of the reactive gas-timing technique as a powerful tool for the rational design of metal-oxynitride films, paving the way for their application in advanced electronic devices.
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Reusability, Long-Life Storage and Highly Sensitive Zirconium Nitride (ZrN) Surface-Enhanced Raman Spectroscopy (SERS) Substrate Fabricated by Reactive Gas-Timing Rf Magnetron Sputtering
(2023-12-22)
Sucheewa, Nguentra
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Wongwiriyapan, Winadda
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Rattanawarinchai, Prapakorn
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Wuttikhun, Tuksadon
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Sinthiptharakoon, Kittiphat
Transition metal nitrides (TMN) are promising material alternative to replace noble metals in the field of plasmonic applications, especially surface-enhanced Raman spectroscopy (SERS). Here we demonstrate a practical surface enhanced Raman spectroscopy (SERS) substrate using zirconium nitride (ZrN) thin films grown by reactive gas-timing (RGT) rf magnetron sputtering. The tailored properties of ZrN thin film exploited for SERS activity could be achieved to obtain a highly sensitive ZrN thin film SERS substrate with the enhancement factor (EF) of 1.24 × 106 and 4.8 %RSD at 1626 cm-1 toward methylene blue (MB) analyte which are comparable to the optimized Au sputtered thin films (EF=1.18 × 106 and with 5.1%RSD). We find that the spatial plasmonic hotspots on the surface of ZrN SERS substrate controlled by the turn-on timing of Ar:N2 sputtered gas sequence, leading to the discrete conductive surface profile, strongly relates to non-stoichiometric composition and the degree of (200)-oriented texture at the surface of ZrN thin film. Furthermore, ZrN thin film SERS substrates exhibit an excellent recyclability more than 30 cycles with simple cleaning process and a storage time longer than 6 months. The detection and reusability of ZrN SERS substrate on the low concentration of trinitrotoluene (TNT) for homeland security are also performed.
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Effect of amino-, mercapto-silane coupling as a molecular bridge of polyvinyl chloride ion-selective membrane on silicon nitride for nitrate ISFET sensors
(2020-06-01)
Chaisriratanakul, Woraphan
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Bunjongpru, Win
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Pankiew, Apirak
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Srisuwan, Awirut
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Jeamsaksiri, Wutthinan
This paper presents a modification of a Si<inf>3</inf>N<inf>4</inf> Polyvinyl chloride (PVC) membrane on a surface of an ion selective field effect transistor (ISFET) using silane with two different functional groups for comparison of nitrate sensing characteristics. Effects of amino (NH<inf>2</inf>) and thiol groups (SH) toward structures and characteristics of nitrate sensors were analyzed using the following techniques: ellipsometry, scanning electron microscope (SEM), infrared spectroscopy (FTIR), zeta potential and electrochemical impedance spectroscopy (EIS). After surface modification, the thickness of the silane layers for both cases were similar with uniform surface topology. Absolute zeta potentials of PVC ion-selective membrane (7.65 mV) and Si<inf>3</inf>N<inf>4</inf> surface modification with MPTMS (-51.46 mV) reflected the surface functional group and showed that membranes could be bonded to the PVC ion-selective membrane. Since APTMS produced higher EIS than MPTMS, the resulting nitrate sensors modified by MPTMS had higher sensitivity than the sensors with APTMS. Finally, the modified sensors had a useful life time of 3 months.
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Modification of polyvinyl chloride ion-selective membrane for nitrate ISFET sensors
(2020-05-15)
Chaisrirattanakua, Woraphan
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Bunjongpru, Win
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Pankiew, Apirak
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Srisuwan, Awirut
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Jeamsaksiri, Wutthinan
In this work, a Polyvinyl Chloride (PVC) ion-selective membrane was modified to detect nitrate based on Ion Selective Field Effect Transistor (ISFET) sensing technology in order to eliminate chloride interference. A modification was done with ethylenediamine solution to achieve animated PVC, which was then oxidized with sodium tungstate to form nitrone coated PVC membrane. The modified PVC was characterized using FTIR, 1H NMR, GPC, FE-SEM and EIS. The FTIR spectrum of animate PVC demonstrated -NH<inf>2</inf> bending at 1580 cm−1, NO<inf>2</inf> asymmetric stretching at 1650 cm−1 and N[sbnd]O out-of-plane deformation vibration at 837 cm−1. GPC analysis of the modified PVC showed that the PVC molecular weight was shifted to a high molecular weight. The PVC ion-selective membrane was immobilized on the ISFET to create nitrate sensors with the following characteristics. The Nitrate-Nitrogen detection limit is 1.20 ppm with linear range from 3−20 ppm at sensitivity of 56 ± 2 mV/dec. The sensor is useful for detecting small amount of nitrate in a mixed solution, which usually is the case in most situations. This sensor could be applied in many applications, such as agricultural industry, water reserve management and medical field as well.
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Effects of thermal treatment on hydrophilicity and corrosion resistance of Ti surface
(2019-03-01)
Boonrungsiman, Suwimon
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Prompinit, Panida
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Khemthong, Pongtanawat
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Wutikhun, Tuksadon
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Treethong, Alongkot
Surface treatment of titanium (Ti) surface has been extensively studied to improve its properties for biomedical applications, including hydrophilicity, corrosion resistance, and tissue integration. In this present work, we present the effects of thermal oxidation as surface modification method on metallic titanium (Ti). The Ti foils were oxidized at 300°C, 400°C, 500°C, and 600°C under air atmosphere for 3 hours, which formed oxide layer on Ti surface. The physicochemical properties including surface chemistry, roughness, and thickness of the oxide layer were evaluated in order to investigate how these factors affected surface hydrophilicity, microhardness, and corrosion resistance properties of the Ti surface. The results revealed that surfaces of all oxidized samples were modified by formation of titanium dioxide layer, of which morphology, phase, and thickness were changed according to the oxidized temperatures. Increasing oxidation temperature led to the formation of thicker oxide layer and phase transformation of anatase to rutile. The presence of the oxide layer helped the improvement of corrosion resistance and microhardness. The most improvement in surface roughness was found in the specimens treated at 400°C, which significantly improved surface hydrophilicity. But both surface roughness and hydrophilicity reduced when oxidized at 500°C and 600°C, suggesting that hydrophilicity was dominated by the surface roughness. In addition, this surface treatment did not reduce the biocompatibility of the metallic Ti substrates against murine osteoblasts (MC3T3).
1
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Crucial role of reactive pulse-gas on a sputtered Zn3N2 thin film formation
(2016-01-01)
Khemasiri, Narathon
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Chananonnawathorn, Chanunthorn
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Klamchuen, Annop
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Jessadaluk, Sukittaya
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Pankiew, Apirak
Herein, we demonstrate a powerful technique, known as reactive gas-timing (RGT) rf magnetron sputtering, to fabricate high quality Zn<inf>3</inf>N<inf>2</inf> thin films at room temperature without applying any additional energy sources. A single phase of Zn<inf>3</inf>N<inf>2</inf> film formation can only be obtained when a reactive pulse-gas of N<inf>2</inf> is utilized. We find that selecting a small atomic mass of sputtered reactive gas coupled with the pulse-gas technique is very crucial to adjust the number of sputtered atoms obtained from the target and enrich the forming energy of the sputtered Zn<inf>3</inf>N<inf>2</inf> films during the deposition process. Our results highlight that the RGT technique is a promising method to fabricate high quality sputtered compound thin films that can be applied in flexible devices. A simplified model of the materials system at the surface region of the de-nitride Zn<inf>3</inf>N<inf>2</inf> during ion bombardment is also presented.
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High sensitive nanocrystal titanium nitride EG-FET pH sensor
(2013-10-29)
Rayanasukha, Yossawat
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Porntheeraphat, Supanit
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Bunjongpru, Win
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Khemasiri, Narathon
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Pankiew, Apirak
Solid state pH-sensor device with high efficiency has successfully prepared by using TiN thin film as sensing membrane of extended gate field effect transistor (EG-FET) device. This research has described the physical properties and sensing characteristics of TiN membrane thin film which deposited on SiO<inf>2</inf>/Si substrate through reactive D.C. magnetron sputtering system. Thenanocrytal-TiNwith anatasestructure depended on substrate heating conditions was revealed from glancing angle x-ray diffraction. The I<inf>DS</inf>-V<inf>GS</inf> measurement in the standard buffer solutions showed that the sensitivity of fabricated TiN-EGFET pH deviceis 59.82mV/pH. © (2013) Trans Tech Publications, Switzerland.
1
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Fabrication of low cost anodic aluminum oxide (AAO) tubular membrane and their application for hemodialysis
(2012-10-16)
Kasi, Ajab Khan
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Kasi, Jafar Khan
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Hasan, Mahadi
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Afzulpurkar, Nitin
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Pratontep, Sirapat
This paper reports the fabrication of AAO tubular membrane using 99.35% and 99.58% pure Al and their potential application for hemodialysis. Here we discussed the effect of impurity on membrane structure. We found that the self organized structure of AAO nanochannels minimize the impurity defects in AAO membrane. If micro size impurity blocks the generation of AAO nanochannels then the neighboring nanochannels bend and make branches to fulfill that gap. We observed that if impurity size is less than the AAO membrane thickness then it does not produce micro size hole. In low grade Al the periodic hexagonal order was disturbed however there was no big difference in pore diameter. It was observed that such type of membrane does not suffer from leakage problem and it can be used for filtration. The fabricated tubular membrane was used for hemodialysis successfully. The hemodialysis results show that AAO tubular membrane can be used for both diffusive and convective filtration. © (2012) Trans Tech Publications, Switzerland.

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