The development of a large-area solution process for CuO nanowires, which are promising p-type thin film transistors (TFT) channel materials, is required. To overcome the limitations of the existing high-vacuum and high-cost deposition process, a large-area Cu nanowire network was formed on the substrate using the Mayer rod coating method, and a CuO channel was implemented by subsequent thermal annealing. Consequently, p-type TFT with an on/off current ratio of 1.4×10⁴ and a field-effect mobility µ_FE≈10^-4 cm²/(V⋅s). was fabricated and optimized. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses showed that the sample annealed at 200°C exhibited an incomplete oxidation state with a mixed Cu/Cu₂O phase and a high fraction of M-OH species (58.78%), resulting in a low on/off current ratio (≈1.2). In contrast, annealing at 450°C leads to a CuOdominant phase, where the fraction of lattice oxygen(O1) increases to 31.11% and the oxygen vacancy (VO) component increases to 7.15%, indicating a significant improvement in hole concentration and charge transport. These phase transitions and surface chemical changes are identified as the key mechanisms for the enhanced TFT switching characteristics. The low-cost, large-area Mayer rodbased solution process proposed in this study provides a basic process platform for p-type TFTs applicable to flexible wearables and display technologies and suggests the possibility of commercialization through additional optimization of bias stability in the future.

In this study, the effect of vanadium oxide (V₂O₅) content and pre-sintering atmosphere on sealing property of glass frit that consisted of V₂O₅-BaO-ZnO-P₂O₅-TeO₂-CuO-Fe₂O₃ SeO₂ was investigated by XPS (X-ray photoelectron spectroscopy). The content of V₂O₅ was changed to 15, 30, and 45 mol%, and the pre-sintering was carried out in air and N₂ condition, respectively. XPS analysis conducted before and after laser irradiation with identical sample. Before laser treatment, glass frits that were pre-sintered at air condition showed both V₄₊and V₅₊, but the valence state was changed to V₅₊ after laser irradiation when the glass frits contained 30 and 45 mol% V₂O₅; this change led to non-adhesive property. On the other hand, glass frits that were pre-sintered at N₂ condition exhibited only V₄₊ and it showed fine adhesion irrespective of the V₂O₅ content. As a result, the existence of V₄₊ seems to be a major factor for controlling the adhesive property of glass frit for laser sealing.

Zinc tin oxide transparent thin film transistors (ZTO TTFTs) were fabricated on oxidized n+ Si wafers. The thickness of 30 nm Al2O3 films were deposited on the oxidized Si wafers by atomic layer deposition, which acted as the gate insulators of ZTO TTFTs. The Al2O3 films were rapid-annealed at 400 , 600 , 800 , and 1,000 , respectively. Active layers of ZTO films were deposited on the Al2O3/SiO2 coated n+ Si wafers by rf magnetron sputtering. Mobility and threshold voltage were measured as a function of the rapid-annealing temperature. X-ray photoelectron spectroscopy (XPS) were carried out to observe the chemical bindings of Al2O3 films. The annealing effects of gate-insulator on the properties of TTFTs were analyzed based on the results of XPS.

Ti was deposited on the Al substrate using DC magnetron sputtering with changing the N2 gas for the possible application of a solar absorbing layer. N2 gas ranged from 50 to 75 sccm was systematically applied in the 5 sccm interval and the variation of the absorption rate was investigated. Microstructural examination and elemental analysis indicate that Ti was reacted with N2 gas and formed TiNOx compound. As compared with the film without any exposure of N2 gas, absorption rate improved by more than 20%. Typically the average absorption of TiNOx fim with 65% of N2 gas was about 99% in the visible range, and the average absorption was more than 90% in the infrared absorption region respectively.

Bottom-gate tin oxide (SnO2) thin film transistors (TFTs) were fabricated on N+ Si wafersused as gate electrodes. 60-nm-thick SnO2 thin films acting as active layers were sputtered onSiO2/Al2O3 films. The SiO2/Al2O3 films deposited on the Si wafers were employed for gate dielectrics. Inorder to increase the resistivity of the SnO2 thin films, oxygen mixed with argon was introduced into thechamber during the sputtering. The mobility of SnO2 TFTs was measured as a function of the flow ratioof oxygen to argon (O2/Ar). The mobility variation with O2/Ar was analyzed through studies oncrystallinity, oxygen binding state, optical properties. X-ray diffraction (XRD) and XPS (X-rayphotoelectron spectroscopy) were carried out to observe the crystallinity and oxygen binding state ofSnO2 films. The mobility decreased with increasing O2/Ar. It was found that the decrease of the mobilityis mainly due to the decrease in the polarizability of SnO2 films.

In this paper, we carried out the investigations of both etch characteristics and mechanisms for the SnO2 thin films in O2/BCl3/Ar plasma. The dry etching characteristics of the SnO2 thin films was studied by varying the O2/BCl3/Ar gas mixing ratio. We determined the optimized process conditions that were as follows: a RF power of 700 W, a DC-bias voltage of -150 V, and a process pressure of 2 Pa. The maximum etch rate was 509.9 nm/min in O2/BCl3/Ar=(3:4:16 sccm) plasma. From XPS analysis, the etch mechanism of the SnO2 thin films in the O2/BCl3/Ar plasma can be identified as the ion-assisted chemical reaction while the role of ion bombardment includes the destruction of the metal-oxide bonds as well as the cleaning of the etched surface form the reaction products.

Mg doped zinc tin oxide (ZTOMg) thin films were prepared on glasses by rf magnetron sputtering. O was introduced into the chamber during the sputtering. The optical properties of the films as a function of oxygen flow rate were studied. The crystal structure, elementary properties, and depth profiles of the films were investigated by X-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and secondary ion mass spectrometry (SIMS), respectively. Bottom-gate trdnsparent thin film transistors were fabricated on N Si wafers, and the variation of mobility, threshold voltage etc. with the oxygen flow rate were observed.

In this paper, we investigated the etching characteristics of the TaN thin films and the surface reaction of TaN thin films after etching process. The etching characteristics of the TaN thin films were carried out using inductively coupled plasma (ICP). The etch rate and the selectivity of TaN to SiO2 and TaN to PR were measured by varying the gas mixing ratio, RF power, DC-bias voltage, and process pressure in CF-based plasma. The surface reaction of TaN thin films were determined by x-ray photoelectron spectroscopy (XPS).

Niobium oxide(Nb2O5) films were deposited on p-type Si wafers at room temperature using in-line pulsed-DC magnetron sputtering system with various frequencies. The different duty ratios were obtained by varying the frequency of pulsed DC power from 100 to 300 kHz at the fixed reverse time of 1.5 μs. From the thickness of the sputtered NbOx films, it was possible to obtain much higher deposition rate in case of pulsed-DC sputtering than RF sputtering. However, the similar leakage currents and structural characteristics were obtained from the metal-insulator-semiconductor(MIS) structure fabricated with the NbOx films and the x-ray photoelectron spectroscopy(XPS) results in spite of the different deposition rates. From the experimental results, the NbOx films sputtered by pulsed-DC sputtering are expected to be used in the fabrication process instead of RF sputtering.

We investigated the dry etching characteristics of TiN in TiN/A12O3: gate stack using a inductively coupled plasma system. TiN thin film is etched by BCI3/He plasma. The etching parameters are the gas mixing ratio, the RF power, the DC-bias voltages and process pressures. The highest etch rate is in BClilHe (25%:75%) plasma. The selectivity of TIN thin film to Al2O3 is pretty similar with BCI3/He plasma, The chemical reactions of the etched TiN thin films arc investigated by X - ray photoelectron spectroscopy, The intensities of the Ti 2p and the N is peaks are modified by BCl3: plasma, Intensity and binding energy of Ti and N could be changed due to a chemical reaction on the surface of TiN thin films. Also we investigated that the non volatile byproducts such as TiClx formed by chemical reaction with CI radicals on the surface of TiN thin films.

In this study, the surface modification for a silicon(Si) mold using CHF3 inductively coupled plasma(ICP). The conditions under that plasma was treated a input ICP power 600 W, an operating gas pressure of 10 mTorr and plasma exposure time of 30 sec. The Si mold surface became hydrophobic after plasma treatment in order to CF(x)(X= 1,2,3) polymer. However, as the de-molding process repeated, it was investigated that the contact angle of Si surface was decreased. So, we attempted to investigate the degradation mechanism of the accurate pattern transfer with increasing the count of the de-molding process using scanning electron microscope (SEM), contact angle, and x-ray photoelectron spectroscopy (XPS) analysis of Si mold surface.

In this study, the etching characteristics of Al2O3 thin films were investigated using an ICP (inductively coupled plasma) of BCl3/Ar gas mixture. The etch rate of Al2O3 thin films as well as the SiO2/Al2O3 etch selectivity were measured as functions of BCl3/Ar mixing ratio (0∼100% Ar) at a constant gas pressure (10 mTorr), total gas flow rate (40 sccm), input power (800 W) and bias power (100 W). The behavior of the Al2O3 etch rate was shown to be quite typical for ion-assisted etch processes with a dominant chemical etch pathway. To analyze the etching mechanism using DLP (double langmuir probe), OES (optical emission spectroscopy) and surface analysis using XPS (x-ray photoelectron spectroscopy) were carried out.

This work, the etching characteristics of Ba2Ti9O20(BTO) thin films were investigated using an inductively coupled plasma (ICP) of Ar/Cl2 gas mixture. The etch rate of BTO thin films as well as the BTO/SiO2 and BTO/PR etch selectivity were measured as functions of Ar/Cl2 mixing ratio (0∼100% Ar) at a constants gas pressure (6 mTorr), total gas flow rate (50 sccm), input power (700 W) and bias power (200 W). The etch rate of BTO thin films decreased with increasing Ar fraction. To analyze the etching mechanism an optical emission spectroscopy (OES), double Langmuir probe(DLP) and surface analysis using X-ray photoelectron spectroscopy (XPS) were carried out.

In this work, the etching characteristics of ZnO thin films were investigated using an inductively coupled plasma(ICP) of HBr/Ar/CHF3 gas mixtures. The plasma characteristics were analyzed by a quadrupole mass spectrometer (QMS) and double langmuir probe (DLP). The surface reaction of the ZnO thin films was investigated using X-ray photoelectron spectroscopy (XPS). The etch rate of ZnO was measured as a function of the CHF3 mixing ratio in the range of 0-15% in an HBr:Ar=5:2 plasma at a fixed gas pressure (6mTorr), input power (700 W), bias power (200 W) and total gas flow rate(50sccm). The etch rate of the ZnO films decreased with increasing CHF3 fraction due to the etch-blocking polymer layer formation.