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In this paper, we describe our fabrication of a solution-processed organic thin-film transistor (OTFT) with 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) as the organic semiconductor (OSC) and methyl-siloxane-based spin-on glass (SOG) as the inorganic gate dielectric. Also, we compare these results with OTFTs using different substrates such as a silicon wafer or a polyethersulfone (PES) substrate. From electrical measurements, we observed exemplary I – V characteristics for these TFTs. We calculated the field effect mobility to be 0.007 cm 2 /V s for an OTFT fabricated on a wafer and 0.004 cm 2 /V s for an OTFT fabricated on a PES substrate.

In this study, we have developed high performance TFT (thin film transistor) and a 7.4-inch high resolution LCD (liquid crystal display) panel of full color WSXGA (1600 × RGB × 1024, 257 ppi, 43% aperture ratio) format using ‘sequential lateral solidification (SLS)’ laser crystallization process [Y.J. Kim et al., Grain boundary effect on the characteristics of the high-performance poly-Si TFTs crystallized by SLS Technique, AM-LCD (2005) 249–251]. The gate and data driver circuits were integrated on panel and the integrated drivers comprise a sequential analog sampling data driver and a dual logic gate scanner for redundancy. In addition, we have improved key process for fine image quality. Metal lines used Cu/MoX (5000 A/300 A) for uniform data transfer and array on BM (black matrix) structure for lager aperture ratio was adopted.

We present the latest results of the use of soluble materials such as organic semiconductors (OSCs) or gate-dielectrics for simplified processing of organic thin-film transistors (OTFTs). In this paper, we described our fabrication of a solution-processed OTFT with 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pentacene) as the OSC and siloxane-based spin-on glass (SOG) as the inorganic gate-dielectric. Also, synthesized TIPS-pentacene and SOG were examined for use as the OSC and gate-dielectric in an OTFT. From electrical measurements, we obtained device performance characteristics such as charge carrier mobility, threshold voltage, current ON/OFF ratio, and subthreshold swing, which were 6.48 times 10-3 cm2/V ldr s, -13 V, ~100, and 1.83 V/dec, respectively.

To integrate solution-processible organic semiconductors in the array of thin-film transistors, fine-patterned organic thin-film transistors were fabricated by photolithography. Gold, which has a high work function, was used as a source–drain electrode to reduce the energy barrier between the organic semiconductor and the source–drain. Stacked double layers of gold and chromium were deposited and etched on a glass substrate to enhance the poor adhesion of gold on glass, and then a self-assembled monolayer was formed on them. Solutions of an organic semiconductor and a low-k organic gate insulator were spun by a spin coater and patterned by dry etching using a gate metal as a mask. The devices fabricated by this method show good electrical properties, average field effect mobilities of 0.2–0.3 cm2 V-1 s-1, and an on/off current ratio of over 105 in device dimensions of W/L=84/6 µm. The leakage current through the gate insulator between the gate and the source–drain was similar to that of SiNx in amorphous silicon thin-film transistor (a-Si TFT), which is lower than 10 pA. When the bias-stress stability of organic thin film transistors (OTFTs) was compared with that of a-Si TFT, the threshold voltage shift of OTFT was comparable to that of a-Si TFT, which is smaller than 1 V. However, the stability of OTFT should be further improved and discussed.

The authors report the fabrication of solution-processed 6,13-bis(triisopropylsilylethynyl) (TIPS) pentacene thin-film transistors with a cross-linked poly-4-vinylphenol (PVP) dielectric on a polyethersulphone (PES) substrate. The device exhibited useful electrical characteristics, including a saturation field effect mobility of 2.08 × 10−2 cm2 V−1 s−1, a current on/off ratio of 105, a threshold voltage of −2 V and an excellent subthreshold slope of 0.86 V/dec. It was demonstrated that the significant improvement in the subthreshold slope of TIPS-pentacene TFTs could be attributed to a decreased carrier trap density at the PVP/TIPS-pentacene film interface. Furthermore, a 1,2,3,4-tetrahydronaphthalene (Tetralin) solvent used in this study had a high boiling point, which had a positive effect on the morphology and the molecular ordering of the TIPS-pentacene film.

End substitution of sexithiophene with hexyl groups, α,ω-dihexylsexithiophene (DH-6T), leads to a highly soluble conjugated oligomer. In this paper, we report on the synthesis of an air-stable p-type organic semiconductor, DH-6T. We also report on our analysis of its thermal, optical, and electrical properties. We obtained a stable characteristic curve. The field-effect performance had a mobility of 3.29×10−4cm2∕Vs, while the threshold voltage was about −19V. The current on/off ratio was greater than 106 when the gate voltage was scanned from −40to0V.

Simple p-channel poly-Si TFT (Thin Film Transistor) structure (PMOS 4mask structure) for AMLCD (active matrix liquid crystal display) was developed. Compared with a conventional PMOS 6mask process, two photo mask steps, passivation-hole mask and pixel mask, has been eliminated to create 4mask process. Both ELA (Eximer Laser Annealing) and SLS (Sequential Lateral Solidification) method were used for the formation of a poly-Si. By using PMOS 4mask process, 10.4-inch XGA (1024×768) AMLCD panel with integration of the gate-driver and demultiplexer was successfully realized.

DC stress induced degradation was compared between LTPS short channel LDD NMOSFETs and PMOSFETs with a dimension of W/L = 3/3 μm/μm by degradation mapping of device parameters. Asymmetric degradation phenomena were classified for different type of devices and compared with respect to applied bias and power.

High-quality thin films were deposited by charged liquid cluster beam (CLCB) method using a strontium carboxylate with a sol-gel processed Ti precursor at substrate temperatures of 400 and 500°C. The film deposited at 400°C was crystallized at 600-700°C to give a granular structure (film I) while the film deposited at 500°C (film II) gave a columnar structure of high crystallinity without postannealing. The grain growth and electric properties, such as dielectric constant, dissipation factor, leakage current density, and breakdown field, of films I and II were compared. © 2004 The Electrochemical Society. All rights reserved.

High-quality barium strontium titanate (BST) thin films were fabricated using charged liquid cluster beam (CLCB) method. The X-ray diffraction patterns of the as-deposited BST films indicated that the perovskite phase appeared at 450°C without any intermediate phase and high film crystallinity was achieved at 500°C. The Ba:Sr:Ti ratio in the precursor solution was transferred to the deposited film without any loss. The crystallinity, dielectric constant, dissipation factor, and leakage current density were measured and compared for the as-deposited films prepared at 500°C and the films deposited at 400°C and postannealed at 700°C.