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Paper transistors have the advantages of recyclability, high abundance, low cost, disposability, and biodegradability. In this paper, a nonvolatile transistor fabricated on a paper substrate without protective layers by using solution-based methods is presented, and promising performance is reported. The memory window of ferroelectric field-effect transistors is approximately 16 V when the gate voltage is swept from +20 V to -20 V. The on/off ratio is 3.45 × 102, even on the paper substrate. Electrical characteristics of the memory device are not degraded, as compared with those of transistors on rigid substrates fabricated simultaneously.

In this work, metal–ferroelectric–semiconductor field-effect transistors (MFSFETs) have been fabricated for the first time using poly(vinylidene fluoride) (PVDF) and polyvinylidene fluoride trifluoroethylene [P(VDF-TrFE)] thin films as ferroelectric layer. PVDF and P(VDF-TrFE) thin films were fabricated by sol–gel method on Si(100) wafers. The drain current–gate voltage (ID–VG) characteristics of the fabricated MFSFETs with PVDF and P(VDF-TrFE) thin films exhibited very good ferroelectric hysteretic curves with counterclockwise loop same to those of other ferroelectric materials. It also demonstrates a realizable possibility of one-transistor type (1T-type) ferroelectric memory without a buffer layer using thin organic material. The absence of a buffer layer presents many advantages such as the elimination of the depolarization field, leakage current influence of the thin buffer layer, reduction of the process steps, low-operational voltage, and low-power consumption. The MFSFETs using PVDF and P(VDF-TrFE) thin films as ferroelectric layer have promising potential for use in low-voltage operable and flexible 1T-type ferroelectric random access memory (FeRAM) using organic material. On the other hand, it also has been attempted to make ferroelectric field-effect transistors (FeFETs) with blended PVDF/P(VDF-TrFE) films in order to compare the P(VDF-TrFE) films. The ferroelectric films for metal–ferroelectric-metal (MFM) capacitors have been fabricated using the blended PVDF/P(VDF-TrFE) solutions with different concentrations by sol–gel method. Ferroelectric field-effect transistors using poly(3-hexylthiopene) (P3HT) channel layer have also been fabricated on TiN substrates in order to compare the device characteristics of the pure P(VDF-TrFE) and blended PVDF/P(VDF-TrFE) thin films in this study.

This study demonstrates a new and realizable possibility of 1T-type ferroelectric random access memory devices using an all solution processing method with cellulose paper substrates. A ferroelectric poly(vinylidene fluoride–trifluoroethylene) (P(VDF-TrFE)) thin film was formed on a paper substrate with an Al electrode for the bottom-gate structure, and then a semiconducting poly(3-hexylthiophene) (P3HT) thin film was formed on the P(VDF-TrFE)/paper structure using a spin-coating technique. The fabricated ferroelectric gate field-effect transistors (FeFETs) on the cellulose paper substrates demonstrated excellent ferroelectric property with a memory window width of 20 V for a bias voltage sweep from −30 to 30 V, and the on/off ratio of the device was approximately 102. These results agree well with those of the FeFETs fabricated on a rigid Si substrate. In order to compare and check the reproducibility of the characteristics of the FeFETs on the paper substrate, it also has been attempted to make FeFETs with various channel length and width ratios were fabricated. From the measured characteristic results, it can be seen that the electrical properties of FeFETs are almost similar regardless of the substrate type. These results will lead to the emergence of printable electron devices on paper. Furthermore, these nonvolatile paper memory devices, which are fabricated by a solution processing method, are reliable, very inexpensive; have a high density; and can be fabricated easily.

The flexible organic non-volatile ferroelectric field-effect transistors (FeFETs) with poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] was fabricated on polyimide and aluminum foil substrates. Al foil has merit of flexibility because of ultraflexible and ultrathin properties. It can be bent with small bend radius and even folded. It serves as bottom gate electrode in itself as well. Thus, an expensive fabrication step, evaporation of bottom gate, can be removed. In spite of these merits of Al foil, it is difficult to fabricate FeFETs on it owing to difficulty in handling: Al foil wrinkles easily and cannot be flattened during fabrication. The regioregular poly(3-hexylthiophene) [P3HT] film was formed as an active layer by the sol–gel method at low temperature. In case of the fabricated FeFETs on polyimide substrates, the field-effect mobility was ~0.28 cm2/Vs, the on/off ratio was approximately 5.6 × 103, and the memory window (threshold voltage shift) was approximately 7 V. It has ~103 of current on/off ratio and about 7–8 V of memory window for the Al foil substrates.

OBJECTIVES In this paper, we proposed an algorithm for recognizing a rotator cuff supraspinatus tendon tear using a texture analysis based on a histogram, gray level co-occurrence matrix (GLCM), and gray level run length matrix (GLRLM). METHODS First, we applied a total of 57 features (5 first order descriptors, 40 GLCM features, and 12 GLRLM features) to each rotator cuff region of interest. Our results show that first order statistics (mean, skewness, entropy, energy, smoothness), GLCM (correlation, contrast, energy, entropy, difference entropy, homogeneity, maximum probability, sum average, sum entropy), and GLRLM features are helpful to distinguish a normal supraspinatus tendon and an abnormal supraspinatus tendon. The statistical significance of these features is verified using a t-test. The support vector machine classification showed accuracy using feature combinations. Support Vector Machine offers good performance with a small amount of training data. Sensitivity, specificity, and accuracy are used to evaluate performance of a classification test. RESULTS From the results, first order statics features and GLCM and GLRLM features afford 95%, 85%, and 100% accuracy, respectively. First order statistics and GLCM and GLRLM features in combination provided 100% accuracy. Combinations that include GLRLM features had high accuracy. GLRLM features were confirmed as highly accurate features for classified normal and abnormal. CONCLUSIONS This algorithm will be helpful to diagnose supraspinatus tendon tear on ultrasound images.

Social media is an emerging issue in content services and in current business environment. YouTube is the most representative social media service in the world. YouTube is different from other conventional content services in its open user participation and contents creation methods. To promote a content in YouTube, it is important to understand the diffusion phenomena of contents and the network structural characteristics. Most previous studies analyzed impact factors of contents diffusion from the view point of general behavioral factors. Currently some researchers use network structure factors. However, these two approaches have been used separately. However this study tries to analyze the general impact factors on the view count and content based network structures all together. In addition, when building a content based network, this study forms the network structure by analyzing user comments on 22,370 contents of YouTube not based on the individual user based network. From this study, we re-proved statistically the causal relations between view count and not only general factors but also network factors. Moreover by analyzing this integrated research model, we found that these factors affect the view count of YouTube according to the following order; Uploader Followers, Video Age, Betweenness Centrality, Comments, Closeness Centrality, Clustering Coefficient and Rating. However Degree Centrality and Eigenvector Centrality affect the view count negatively. From this research some strategic points for the utilizing of contents diffusion are as followings. First, it is needed to manage general factors such as the number of uploader followers or subscribers, the video age, the number of comments, average rating points, and etc. The impact of average rating points is not so much important as we thought before. However, it is needed to increase the number of uploader followers strategically and sustain the contents in the service as long as possible. Second, we need to pay attention to the impacts of betweenness centrality and closeness centrality among other network factors. Users seems to search the related subject or similar contents after watching a content. It is needed to shorten the distance between other popular contents in the service. Namely, this study showed that it is beneficial for increasing view counts by decreasing the number of search attempts and increasing similarity with many other contents. This is consistent with the result of the clustering coefficient impact analysis. Third, it is important to notice the negative impact of degree centrality and eigenvector centrality on the view count. If the number of connections with other contents is too much increased it means there are many similar contents and eventually it might distribute the view counts. Moreover, too high eigenvector centrality means that there are connections with popular contents around the content, and it might lose the view count because of the impact of the popular contents. It would be better to avoid connections with too powerful popular contents. From this study we analyzed the phenomenon and verified diffusion factors of Youtube contents by using an integrated model consisting of general factors and network structure factors. From the viewpoints of social contribution, this study might provide useful information to music or movie industry or other contents vendors for their effective contents services. This research provides basic schemes that can be applied strategically in online contents marketing. One of the limitations of this study is that this study formed a contents based network for the network structure analysis. It might be an indirect method to see the content network structure. We can use more various methods to establish direct content network. Further researches include more detailed researches like an analysis according to the types of contents or domains or characteristics of the contents or users, and etc.

We fabricated a metal-ferroelectric-insulator-semiconductor structure using a poly(vinylidene fluoride trifluorethylene) as a ferroelectric layer and a cyanoethyl pullulan as an insulating buffer layer for the first time. The CEP thin films were deposited on Si substrate by using a sol-gel method. The coated P(VDF-TrFE) films on CEP/Si structure were crystallized. For the Au/P(VDF-TrFE)/CEP/Si structure, the capacitance-voltage characteristics showed hysteresis loops, the memory window width was about 4.6V at a bias sweep range of ±5V. The leakage current density was about 5.5 × 10−7 A/cm2 at 5V for the thick film from the 5 wt% solution.

Various surfaces have been used for deoxyribonucleic acid (DNA) immobilization, one example being a silanized surface. This is useful for determining DNA lengths and, thus, locating specific gene sequences in DNA by using fluorescence microscopy and scanning probe microscopy. In this study, we deposited DNA by using the molecular combing method and, we used fluorescence microscopy to study how the chain lengths of n-alkylsilanes affected the surface density of DNA deposited on the silanized surfaces in a tris-ethylenediaminetetraacetic acid (TE) buffer. The forces between a cleaned silicon-nitride (Si3N4) tip and each substrate surface in aqueous buffers at various pH levels (1.0 ~ 9.0) were also studied by using atomic force microscopy to measure the force-distance curves. We explain why the density of lambda bacteriophage DNA (λ-DNA) deposited by using the molecular combing method at pH 8 was lower on the silanized surface with the shorter alkyl chain than it was on the silanized surface with the longer alkyl chain in terms of the electrical double layer (EDL) and the adhesive force.

The electrical and ferroelectric properties with different amounts of chemical bonding states at the polymer/metal interface were examined quantitatively in a ferroelectric copolymer poly(vinylidene fluoride-trifluoroethylene) film sandwiched between the top and bottom electrodes on which the surface had been modified by rapid thermal processing in a N2 atmosphere. The capacitors with the heat-treated bottom electrodes at different temperatures showed a lower charge storing capacitance. Ultraviolet photoelectron spectroscopy showed that the capacitance enhancement and field shift to lower coercive value resulted from the relatively larger increase in anions (N,O) than cations (Ti) and the reduction of N C bonding in the reaction product (TiNxOy) on the surface of the bottom electrode, respectively.

The characteristics of a metal–ferroelectric–insulator–semiconductor structure were investigated using poly(vinylidene fluoride/trifluorethylene)(65/35) as a ferroelectric layer and polyvinyl alcohol as an insulating buffer layer. It was found in the metal–insulator–semiconductor structure that the polyvinyl alcohol obtained from 0.4 wt.% solution gave excellent insulator results with a bias sweep range of ± 5 V. The leakage current densities of the polyvinyl alcohol films obtained from 0.1, 0.4 and 0.7 wt.% solutions amounted to 10−5 A/cm2, 10−6 A/cm2 and 10−7 A/cm2, respectively. Based on these results, the 0.4 wt.% polyvinyl alcohol solution was selected for use in the metal–ferroelectric–insulator–semiconductor structures. The width of the memory window in the metal–ferroelectric–semiconductor and metal–ferroelectric–insulator–semiconductor structures measured at a voltage sweep of ±5 V was 2 V and 3 V respectively, whereas the respective current densities amounted to 10−5 and 10−6 A/cm2 at 5V.

Chemical force microscopy using probe tips subjected to liquid-phase chemical modification enables the study of intermolecular forces on a nanoscale, as well as imaging of the chemical inhomogeneity of a sample’s surface with high spatial resolution. However, in adhesive force measurements, the adhesive force between the tip and the sample could easily be affected by interactions caused by molecules in both the contact and the noncontact parts. A novel method involving local chemical modification of the tip is presented. The method is performed by adding a solution of a modification reagent in ethanol when the cleaned tip is approaching the substrate’s surface. The adhesive forces between the substrate’s surface and various types of tips were investigated using atomic force microscopy. This novel method could be helpful for increasing the resolution of chemical force microscopy and for measuring the contact area between the tip and the substrate’s surface.

This paper discussed the recording process and context of the visual archive which records the cultural heritage in video. The cultural heritage record has a value for permanent preservation by being a core material for national and cultural identity of a country, and has its own value as information. Visual archive is one of the recording methods for cultural heritage along with the static image like a picture and the reports documenting contents in writing. Visual archive is useful for the efficient delivery of information with visual images and audio system. Context should be considered to distinguish between data and information more clearly in the process of production and utilization of information. The transformation process of data to information was studied by considering context during the process of recording cultural heritage in images. As a result, we expect that cultural heritage is classified by knowledge information and becomes a foundation used actively for creating cultural contents.

Precursor films based on poly(vinylidene fluoride-trifluoroethylene) P(VDF-TrFE) and P(VDF-TrFE) blended with Pb(Zr,Ti)O 3 were spin-coated on Si-substrates and subsequently annealed at 170 °C. X-ray diffraction studies showed that the amorphous precursor films crystallize to the γ-phase P(VDF-TrFE) without involving the formation of other polymorphs when the P(VDF-TrFE) is blended with Pb(Zr,Ti)O 3 , resulting in phase mixtures composed of a crystalline γ-phase P(VDF-TrFE) and an amorphous Pb(Zr,Ti)O 3 . A larger memory window width and higher accumulation capacitance, as well as a lower leakage current density are induced by the blended Pb(Zr,Ti)O 3 within the low operating voltage ranges from − 3.0 to 3.0 V and from − 2.0 to 2.0 V for 20 wt% and 40 wt% Pb(Zr,Ti)O 3 blending, respectively. These improvements not only in the hysteretic capacitance–voltage characteristics but also in the leakage current density–electric field are directly correlated with the phase mixtures, their volume fraction, dipole moments, and formation of interface layer between the blended film and Si substrate.

Precursor films based on poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) and P(VDF-TrFE) blended with Pb(Zr,Ti)O3 were deposited on Si (100) substrates by spin-coating, and subsequently annealed at 443 K for 0.5 h. These films were then characterized using X-ray diffraction, atomic force microscopy and capacitance-voltage curves. Blending the precursor films of Pb(Zr,Ti)O3 with P(VDF-TrFE) led to the formation of an amorphous oxide whose concentration was proportional to the Pb(Zr,Ti)O3 content. This resulted in extension of the memory-window width with a large voltage difference ranging from 0.07 V to 4.5 V for metal-ferroelectric-silicon capacitors. Moreover, the formation of the amorphous oxide resulted in parallel shifts toward positive or negative voltages in the capacitance-voltage curves because of the fixed negative or positive charge of the oxide at the ferroelectric/Si-substrate interface. These tunable ferroelectric properties open up possibilities for diverse applications and are essential for functional devices, as well as for the commercialization of nonvolatile high-density FeRAM devices.

This study demonstrates a new and realizable possibility of 1T-type ferroelectric random access memory devices using an all solution processing method with cellulose paper substrates. A ferroelectric poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) thin film was formed on a paper substrate with an Al electrode for the bottom gate structure, and then a semiconducting poly(3-hexylthiophene) (P3HT) thin film was formed on the P(VDF-TrFE)/paper structure using a spin-coating technique. The fabricated ferroelectric gate field effect transistors (FeFETs) on the cellulose paper substrates demonstrated excellent ferroelectric property with a memory window width of 20 V for a bias voltage sweep from −30 to 30 V, and the on/off ratio of the device was approximately 102. These results agree well with those of the FeFETs fabricated on a rigid Si substrate. These results will lead to the emergence of printable electron devices on paper. Furthermore, these non-volatile paper memory devices, which are fabricated by a solution processing method, are reliable, very inexpensive, have a high-density, and can be fabricated easily.

In this work, metal–ferroelectric–semiconductor field effect transistors (MFSFETs) have been fabricated for the first time using poly(vinylidene fluoride) (PVDF) and polyvinylidene fluoride trifluoroethylene [P(VDF-TrFE)] thin films as ferroelectric layers. PVDF and P(VDF-TrFE) thin films were fabricated by a sol-gel method on Si(100) wafers. The drain current–gate voltage (I D –V G ) characteristics of both MFSFETs fabricated with PVDF and P(VDF-TrFE) thin films exhibited very good ferroelectric hysteretic curves with a counterclockwise loop that is the same as those of other ferroelectric materials. It also demonstrates the realization of a one-transistor type (1T-type) ferroelectric memory without a buffer layer using thin organic material. The absence of a buffer layer presents many advantages such as the elimination of the depolarization field, leakage current influence of the thin buffer layer, reduction of the process steps, low operational voltage, and low power consumption. MFSFETs using PVDF and P(VDF-TrFE) thin films as ferroelectric layers have promising potential for use in low-voltage and flexible 1T-type ferroelectric random access memory (FeRAM) using organic material.

We propose a color realization method of a reflective display based on quick response-liquid powder display (QR-LPD). We use the particle-moving method in order to address the color particles cyan, magenta, yellow, and black (CMYK) into their respective cells. We fabricated a color addressed reflective display panel using indium-tin-oxide (ITO) glass with a rib width of 15 μm, a cell size of 300 μm × 300 μm, an average particle diameter of 8 μm, and a particle charge to mass ratio (q/m) from +8.5 μC/g to -4 μC/g. Most particles are inserted into their cells on the upper substrate, with non-movable particles removed in a previous step. The fabricated color panel shows a well-addressed CMYK array in microscopic photographs. An additional color display is fabricated using line-by-line addressing in order to facilitate the addressing process.

We propose a new particle-insertion method for a reflective display based on the structure of a quick response-liquid powder display (QR-LPD). To compare this method with the reported simple loading method, two panels are fabricated in the same panel condition of which the width of ribs is 30 μm, the cell size is 220 μm 220 μm, the cell gap is 116-120 μm, the m value of the black particles is μC/g and that for the white particles is μC/g. This method excludes the non-moving particles, inserting only mobile particles into a substrate by using electric fields so that a panel fabricated by the particle-moving method can drive most of the particles in a cell. Also, most of the particles move at the threshold voltage of 40 V with enhanced reflectivity.

Precursor films based on poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) and P(VDF-TrFE) blended with Pb(Zr,Ti)O3 (PZT) were spin-coated on Si substrates and subsequently annealed at 150, 170, or 190°C. X-ray diffraction studies showed that the crystallization from the amorphous precursor films to the £ phase starts at higher annealing temperatures without involving the formation of other polymorphs when the P(VDF-TrFE) is blended with PZT, and the PZT content increases, resulting in an amorphous phase and/or crystalline £ phase. Nevertheless, a larger memory window width and much higher accumulation capacitance are induced by the blended PZT within the low operating voltage ranges from ¹0.5 to 2.0V and from ¹2.0 to 6.0V for 76.7 and 96.7wt% PZT blending, respectively. Furthermore, these improvements in the hysteretic characteristics in the capacitance­voltage measurements are also directly correlated with the degree of P(VDF-TrFE) crystallization and the presence of PZT. This approach enables viable routes toward the commercialization of nonvolatile ferroelectric memory devices and their market extension to potential applications as functional devices.

layer was prepared. The LDO thin film and the SBT film were deposited by using the sol-gel method. The sol-gel-derived LDO thin films on Si had very flat and smooth surface morphologies. The equivalent oxide thickness (EOT) values were about 10.1 nm, 12.5 nm, and 12.8 nm for 750 C, 800 C, and 850 C, respectively. Also, the relative dielectric constants of the 750 C-annealed, 800 C-annealed and 850 C-annealed LDO films were about 15.4, 12.5, and 12.2, respectively. On the whole, the leakage current densities showed good characteristics regardless of the annealing temperature. Especially, the leakage current property of the 850 C-annealed LDO film was visibly superior to those of the others at voltages over 6 V. The C-V characteristics of the Au/SBT/LDO/Si structure showed clockwise hysteresis loops, and the memory window width increased as the bias

Organic thin-film transistors were fabricated with poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) copolymer and cyanoethylpullulan (CyEPL) for the dielectrics. The influence of the double-organic-ferroelectric-layer structure composed of all ferroelectric dielectrics below regioregular poly(3-hexylthiophene) was investigated. The capacitance-voltage (C-V) hysteresis and flatband-voltage shift were found at −5 to +5 V, depending on the field direction. A difference in the transfer characteristic was observed as the effect of the P(VDF-TrFE))/(CyEPL) sandwich structure on the channel layer. Both the space charge at p-Si and the polarization due to the trapped charges affected the field across the ferroelectric dielectrics.

Metal-ferroelectric-insulator-semiconductor structure capacitors with a polyvinylidene fluoride trifluoroethylene (75/25) (PVDF-TrFE) ferroelectric and a lanthanum zirconium oxide ( LaZrO x) insulator layers were fabricated on a p-type Si(100) substrate in this work. The thin films were prepared using the spin-coating method. The LaZrO x thin films were crystallized at 750°C for 30 min in an O 2 ambient. Negligible hysteresis was observed from the C–V (capacitance-voltage) characteristic of the LaZrO x/ Si structure. The equivalent oxide thickness (EOT) was about 8.2 nm. Then the PVDF-TrFE film was spin-coated on the LaZrO x/ Si structure. To crystallize the PVDF-TrFE, the structure was annealed at 165°C for 30 min. The memory window width in the C–V curve of the Au/PVDF - TrFE/LaZrO x/ Si structure was about 4 V for a voltage sweep of ±5 V, and the leakage current density was about 10-8 A/cm 2 at 35 kV/cm for a 100-nm-thick film.

In this study, we fabricated the n-channel metal-ferroelectric-insulator-semiconductor field effect transistors (MFIS-FETs) using an Au/polyvinylidene fluoride-trifluoroethylene P(VDF-TrFE)/ZrO2/Si(100) structures. The ZrO2 thin film had the equivalent oxide thickness (EOT) value of around 9 nm. And the P(VDF-TrFE) film on a ZrO2/Si structure showed good ferroelectric property with memory window width of 2.5 V for a bias voltage sweeping of ±7 V. The leakage current density of this MFIS structure showed very excellent insulation property with about 9 × 10−8 A/cm2 at 5 V. Based on these results, we fabricated and investigated MFIS-FETs with ferroelectric polymer P(VDF-TrFE) film and ZrO2 buffer layer. The memory window width and on/off ratio of the MFIS-FET was about 4.5 V and 103, respectively. These results predicted that the P(VDF-TrFE) thin film would be useful for the realization of 1-transistor type ferroelectric memory.

In this study, we fabricated Organic Field Effect Transistors (OFETs) using an Au/P3HT/SiO2/n++-Si structure. The organic poly(3-hexylthiophene) (P3HT) films with various thickness, which were controlled by changing weight concentration of P3HT in chloroform (CHCl3) solvent, have been fabricated using a sol–gel method. The correlations of mobility and on/off current ratio depend on various thickness of P3HT films are revealed. The mobility of the P3HT films were about 1.1, 2.2, and 2.8 × 10−3 [cm2 V−1 s−1] for 0.4, 0.7, and 1.0 wt %, respectively. We also observed the trade off relation on mobility and on/off ratio with increasing anneal temperature from 100 to 140°C. The surface morphology with various thicknesses was scanned by using atomic force microscopy (AFM) in order to verify the relations between the thickness of film and device performance. We observed the increase of on current with thickness of active layer. These results indicate that the accumulated carriers between semiconductor and insulator are strongly affected by the degree of molecular packing and size of molecular bonding.

The lanthanum zirconium oxide thin films were prepared on p-type Si(100) by a sol-gel wet method. Sol-gel solutions of La x Zr 1 − x O y with La atomic fractions of x = 0, 0.05, 0.1, 0.3, and 0.5 were synthesized for film deposition. Thin films were characterized using x-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM). Electrical property characterization was performed with metal-insulator-semiconductor (MIS) structures through capacitance-voltage (C-V) and current density-voltage (J-V) measurements. The thin film showed a good surface morphology. Equivalent oxide thickness (EOT) values of 30 nm-thick La x Zr 1 − x O y thin films annealed at 700°C were about 8.8–10.5 nm. C-V measurements revealed that curves shifted left when the film has a larger content of La or was annealed at a higher temperature. The leakage current density was below 1.0 × 10−6 A/cm 2 at 1 MV/cm for all samples.

The metal-ferroelectric-semiconductor field effect transistor (MFSFET) was fabricated using polyvinylidene fluoride (PVDF) thin film as a ferroelectric layer. PVDF thin films of 4 and 6 wt% were spin-coated on Si(100) wafers. Ferroelectric hysteretic curves inducing a counterclockwise loop, which means that the deposited PVDF films were crystallized with ferroelectric β phase, was exhibited in the drain current–gate voltage (I D –V G ) characteristics of MFSFET. The memory window widths of the MFSFET were more than 1.6 V. The MFSFET that operates with the PVDF thin film used as a gate dielectric material is shown in the drain current–drain voltage (I D –V D ) characteristics. The MFSFET using PVDF as ferroelectric layer has promising potential for use in low-voltage operable one transistor (1T) type ferroelectric random access memories (FeRAM) using organic material.

The metal-ferroelectric-metal-insulator-semiconductor field-effect transistor using the Au/(Bi,La)4Ti3O12(BLT)/Pt/SrTa2O6(STA)/Si structure is prepared. The STA and BLT films are spun-casted by the sol-gel method. The equivalent oxide thickness value of the STA thin film is 5.2 nm and negligibly small hysteresis loops have been observed for the Au/STA/Si structure. The leakage current density is lower than 10− 7 A/cm2 under 6 V. The remanent polarization of the 420 nm-thick BLT film was 35.2 μ C/cm2 at 450 kV/cm. The Au/BLT/Pt/STA/Si MFMIS-FET was fabricated with different area ratio (AI/AF) from 1 to 8. From the drain current–gate voltage characteristics at the drain voltage of 0.2 V, the memory window is only 0.5 V for the device with AI/AF = 1 but it is increased to 1.8 V as the AI/AF is increased to 8. For the AI/AF ratio of 4, the drain current of 1.2× 10− 5 A rapidly drops after 1.4× 104 s to 4× 10− 6 A. The retention time improves as the AI/AF ratio is increased to 8 and it has been found to drop a...

We fabricated the metal–ferroelectric–semiconductor field effect transistor (MFSFET) using poly(vinylidene fluoride) (PVDF) thin film as a ferroelectric layer. PVDF thin films were prepared by spin-coating PVDF solutions of 2–6 wt % on Si(100) wafers with source and drain diffusion regions. The drain current–gate voltage (ID–VG) characteristics of MFSFET exhibited ferroelectric hysteretic curves inducing a counterclockwise loop similar to that of other ferroelectric materials. It seems that the deposited PVDF films were crystallized with the ferroelectric β phase. The memory window widths of the MFSFET were more than 1.0 V. The drain current–drain voltage (ID–VD) characteristics show that the MFSFET operates with the PVDF thin film used as a gate dielectric material. The MFSFET using PVDF as ferroelectric layer has promising potential for use in low-voltage operable one-transistor (1T)-type ferroelectric random access memories (FeRAMs) using organic material.

We fabricated the n-channel metal-ferroelectric-insulator-semiconductor field-effect transistor (MFIS-FET) using an Au/(Bi,La) 4 Ti 3 O 12 /LaZrO x /Si(100) gate structure. We observed that the LaZrO x thin film had the equivalent oxide thickness value of around 8.7 nm. The 420-nm-thick (Bi,La) 4 Ti 3 O 12 film on a LaZrO x /Si structure, showed a good ferroelectric property and had the width of the memory window of 1.2 V for a bias voltage sweeping of ± 7 V. The drain current-gate voltage (I D -V G ) of an Au/(Bi,La) 4 Ti 3 O 12/ LaZrO x /Si(100) MFIS-FET showed threshold voltage shift (memory window width) owing to the ferroelectric (Bi,La) 4 Ti 3 O 12 film. The drain current-drain voltage (I D -V D ) characteristic curves exhibit typical n-channel field-effect transistor current-voltage characteristic. However, relatively large leakage current observed in the I D –V G and the I D –V D characteristic curves, might be caused by the high density of pores in the BLT film.

In this study, polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) in the composition from 51/49, was deposited on platinum for a metal-ferroelectric-metal structure. From XRD patterns, the 70 nm- and 140 nm-thick PVDF-TrFE films showed the intensity peak of near connected to a ferroelectric phase. Moreover, the thicker film indicated the higher intensity than thinner one. The difference of the remanent polarization (2Pr) at 0 V is decreased gradually from 10.19 to as the thickness decrease from 140 to 70 nm. However, when the thickness decreased to 50 nm, the 2Pr rapidly drop to so the minimum critical thickness might be at least 70 nm for device. Both different thickness films, 70 and 140 nm, indicated that the characteristic of current density-voltage was measured for below 15 V and the thicker film maintained relatively lower current density than thinner one. From these results, we can expect that the electrical properties for the devices particularly ferroelectric thin film transistor using PVDF-TrFE copolymer were able to be on the trade-off relationship between the remanent polarization with the bias voltage and the leakage current.

In this work, we fabricated metal-ferroelectric-semiconductor (MFS) diodes with polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) (51/49) thin films for application to one transistor-type (1T-type) ferroelectric random access memories (FeRAMs). The thin films, with various thicknesses, were prepared on a silicon substrate by using a spin-coating method. The β-phase crystallinity and the grain size of the PVDF-TrFE increased as the film-thickness increased. Typical ferroelectric hysteresis loops were obtained from the capacitance-voltage (C-V) curves. These loops might be considered to be due to the ferroelectric nature of the PVDF-TrFE films. The values of the memory window width for 50-nm-, 150-nm-, and 350-nm-thick PVDF-TrFE films were about 1.4, 2.0, and 3.5 V for a bias sweeping from −5 V to 5 V, respectively. The values of the leakage current density, at a sweeping range of ± 5 V, were about 2.7 × 10−5 A/cm2, 1.1 × 10−5 A/cm2, and 5.6× 10−6 A/cm2 for 50-nm-, 150-nm-, and 350-nm-thick fil...

Ferroelectric SrBi2Ta2O9 (SBT) films on a p-type Si (100) wafer with a LaZrO x (LZO) buffer layer have been fabricated to form a metal-ferroelectric-insulator–semiconductor (MFIS) structure. The LZO thin film and SBT films were deposited by using a sol–gel method. The equivalent oxide thickness (EOT) value of the LZO thin film was about 8.83 nm. Also, the leakage current density of the LZO thin film is about 3.3 × 10−5 A/cm2 at bias sweeping voltage of ±5 V. SBT films were crystallized in polycrystalline phase with highly preferred (115) orientation. Also, the intensity of each pick slightly increased as thickness of SBT films increased. The C–V characteristics of Au/SBT/LZO/Si structure showed clockwise hysteresis loop. The memory window width increased as the thickness of SBT films increased. The leakage current density of Au/SBT/LZO/Si structure decreased as thickness of SBT films increased.

To obtain a metal–ferroelectric–insulator–semiconductor (MFIS) structure, we fabricated ferroelectric SrBi2Ta2O9 (SBT) film on a p-type Si (100) wafer with a LaZrO x (LZO) buffer layer by means of a sol–gel technique. The sol–gel deposited LZO film according to the different annealing temperatures had a good surface morphology even though the crystalline phase was not an amorphous phase. In particular, the root-mean-squared (RMS) surface roughness of the 750-°C-annealed LZO film was about 0.365 nm and its leakage current density was about 8.2 × 10−7 A/cm2 at 10 V. A Au/SBT/LZO/Si structure with different SBT film was fabricated. The C–V characteristics of the Au/SBT/LZO/Si structure showed a clockwise hysteresis loop. The memory window width increased as the SBT film thickness increased. The 600-nm-thick SBT film was crystallized in a polycrystalline phase with a highly preferred (115) orientation. The memory window width of the 600-nm-thick SBT film was about 1.94 V at the bias sweep voltage ±9 V and the leakage current density was about 6.48 × 10−8 A/cm2 at 10 V.

CrB 2 coatings were synthesized on high speed steel (HSS) substrates using inductively coupled plasma (ICP) assisted DC magnetron sputtering, and the structure and properties of the CrB 2 coating produced at different ICP powers and substrate biases were investigated. The hardness of the CrB 2 coatings increased from 30 GPa to 54 GPa by increasing the ICP power as well as the negative substrate bias. By increasing ICP power, the preferred orientation of the CrB 2 coating changed from (101) to (001). The CrB 2 coating showed excellent corrosion resistance. The corrosion resistance of the CrB 2 coatings was also found to be much better than that of the TiB 2 coatings. The adhesion strength of the film could be improved considerably after ICP nitriding of the substrate.

Ferroelectric (Bi,La) 4 Ti 3 O 12 (BLT) thin films were prepared on a p-type Si (100) wafer with a SrTa 2 O 6 (STA) buffer layer for a metal-ferroelectric-insulator-silicon (MFIS) structure. The STA buffer layer was completely crystallized at the high temperature over 800°C. We observed that STA thin films fabricated at 900°C for 3 minutes in O 2 ambient had good insulating properties. Their EOT value was about 5.7 nm. Considering the distribution of the bias voltage on a series capacitor, the ferroelectric BLT and the dielectric STA, BLT thin films with a different thickness were formed on STA/Si structures and characterized by C-V measurement including memory windows. It was found that the memory window width was about 1.5 V for the ±5 V bias sweeping with the 600 nm thick BLT films on STA/Si structure. The leakage current density was about 1.0 × 10−7 A/cm 2 at 5 V. These results are useful and promise the realization of a MFIS structure with the BLT and a STA layer for non-destructive read-out (NDRO) t...