共查询到18条相似文献,搜索用时 15 毫秒
1.
In this study, we have successfully explored the potential of a new bilayer gate dielectric material, composed of Polystyrene (PS), Pluronic P123 Block Copolymer Surfactant (P123) composite thin film and Polyacrylonitrile (PAN) through fabrication of metal insulator metal (MIM) capacitor devices and organic thin film transistors (OTFTs). The conditions for fabrication of PAN and PS-P123 as a bilayer dielectric material are optimized before employing it further as a gate dielectric in OTFTs. Simple solution processable techniques are applied to deposit PAN and PS-P123 as a bilayer dielectric layer on Polyimide (PI) substrates. Contact angle study is further performed to explore the surface property of this bilayer polymer gate dielectric material. This new bilayer dielectric having a k value of 3.7 intermediate to that of PS-P123 composite thin film dielectric (k ∼ 2.8) and PAN dielectric (k ∼ 5.5) has successfully acted as a buffer layer by preventing the direct contact between the organic semiconducting layer and high k PAN dielectric. The OTFT devices based on α,ω-dihexylquaterthiophene (DH4T) incorporated with this bilayer dielectric, has demonstrated a hole mobility of 1.37 × 10−2 and on/off current ratio of 103 which is one of the good values as reported before. Several bending conditions are applied, to explore the charge carrier hopping mechanism involved in deterioration of electrical properties of these OTFTs. Additionally, the electrical performance of OTFTs, which are exposed to open atmosphere for five days, can be interestingly recovered by means of re-baking them respectively at 90 °C. 相似文献
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水基前驱体法制备BST铁电薄膜的研究 总被引:1,自引:0,他引:1
Ba1-SrxTiO3(BST)薄膜具有非线性强、漏电流小、不易疲劳等特点,在高密度动态随机存储器的应用,受到x了极大关注。以水基溶液为前驱体,调整Ti(OC4H9)4与H2O的配比以改变溶胶的黏度,并采用旋涂法制备了BST铁电薄膜。对水基BST前驱体溶液进行了DSC/TG和XRD分析。实验表明,采用较高浓度的水基前驱体,有利于薄膜的形成和均匀性。薄膜的相结构研究表明,随着退火温度的上升,BST薄膜的结晶度上升,而晶粒尺寸随之略有下降。 相似文献
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Amorphous chalcogenide thin films were fabricated by the pulsed laser deposition technique. Thereafter, the stacks of multilayered thin films for reflectors and microcavity were designed for telecommunication wavelength. The prepared multilayered thin films for reflectors show good compatibility. The microcavity structure consists of Ge25Ga5Sb10S65 (doped with Er3+) spacer layer surrounded by two 5-layer As40Se60/Ge25Sb5S70 reflectors. Scanning/transmission electron microscopy results show good periodicity, great adherence and smooth interfaces between the alternating dielectric layers, which confirms a suitable compatibility between different materials. The results demonstrate that the chalcogenides can be used for preparing vertical Bragg reflectors and microcavity with high quality. 相似文献
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为解决类金刚石膜内应力极大的问题,利用很薄的岛状结构锗层与较厚的类金刚石层循环,设计并制备了具有低内应力的多层类金刚石膜。其中,类金刚石层为主要功能膜层,起到硬质保护和光学增透的作用;而锗层作为缓冲层,起到缓解纯类金刚石膜内应力过大的问题,同时由于锗层很薄,对整个膜层的机械性能和红外特性的影响很小。测试表明,制备的多层类金刚石膜内应力为2.14 GPa,比纯类金刚石膜降低了39%,通过了GJB2485-95《光学膜层通用规范》中的重摩擦测试;同时,其纳米硬度仍保持在47 GPa的高水平。该多层类金刚石膜可以作为实际应用的红外窗口保护膜。 相似文献
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Low voltage organic thin film transistors(OTFTs) were created using polymethyl-methacrylate-co g-lyciclyl-methacrylate(PMMA-GMA) as the gate dielectric.The OTFTs performed acceptably at supply voltages of about 10 V.From a densely packed copolymer brush,a leakage current as low as 2×10~(-8) A/cm~2 was obtained.From the measured capacitance-insulator frequency characteristics,a dielectric constant in the range 3.9-5.0 was obtained. By controlling the thickness of the gate dielectric,the threshold voltage ... 相似文献
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PLD法制备高介电调谐率的纳米晶BZT薄膜 总被引:1,自引:0,他引:1
用脉冲激光沉积工艺制备了Ba(ZrxTi1-x)O3(x=0.25,0.30简称BZT25和BZT30)介电薄膜。在650℃原位退火10 min,薄膜为(111)取向柱状生长的晶粒,取向度分别为0.45和0.75。BZT25和BZT30薄膜的平均晶粒尺寸分别为50 nm和60 nm。在室温、1 MHz和3×105 V/cm条件下,BZT25的最大εr和调谐率分别达到563和65%,BZT30的最大εr和调谐率分别达到441和57%。薄膜为(111)取向生长,主要是基于薄膜与底电极Pt界面层立方相结构Pt3Ti的诱导,即(111)Pt3Ti和(111)BZT的晶格匹配。 相似文献
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Thin film transistors (TFTs) with bottom gate and staggered electrodes using atomic layer deposited Al2O3 as gate insulator and radio frequency sputtered In–Ga–Zn Oxide (IGZO) as channel layer are fabricated in this work. The performances of IGZO TFTs with different deposition temperature of Al2O3 are investigated and compared. The experiment results show that the Al2O3 deposition temperature play an important role in the field effect mobility, Ion/Ioff ratio, sub-threshold swing and bias stability of the devices. The TFT with a 250 °C Al2O3 gate insulator shows the best performance; specifically, field effect mobility of 6.3 cm2/Vs, threshold voltage of 5.1 V, Ion/Ioff ratio of 4×107, and sub-threshold swing of 0.56 V/dec. The 250 °C Al2O3 insulator based device also shows a substantially smaller threshold voltage shift of 1.5 V after a 10 V gate voltage is stressed for 1 h, while the value for the 200, 300 and 350 °C Al2O3 insulator based devices are 2.3, 2.6, and 1.64 V, respectively. 相似文献
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P. Gogoi 《Semiconductors》2013,47(3):341-344
The performance of thermally deposited CdS thin film transistors doped with Ag has been reported. Ag-doped CdS thin films have been prepared using chemical method. High dielectric constant rare earth oxide Nd2O3 has been used as gate insulator. The thin film trasistors are fabricated in coplanar electrode structure on ultrasonically cleaned glass substrates with a channel length of 50 μm. The thin film transistors exhibit a high mobility of 4.3 cm2 V?1 s?1 and low threshold voltage of 1 V. The ON-OFF ratio of the thin film transistors is found as 105. The TFTs also exhibit good transconductance and gain band-width product of 1.15 × 10?3 mho and 71 kHz respectively. 相似文献
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Byoung Taek Lee Wan Don Kim Ki Hoon Lee Han Jin Lim Chang Seok Kang Horii Hideki Suk Ho Joo Hong Bae Park Cha Young Yoo Sang In Lee Moon Yong Lee 《Journal of Electronic Materials》1999,28(4):L9-L12
The influence of two-step deposition on the electrical properties of sputtered (Ba,Sr)TiO3 thin films was investigated. BST thin films with thickness 40 nm were deposited by a simple two-step radio frequency-magnetron
sputtering technique, where the BST thin film consisted of a seed layer and a main layer. The dielectric constant was strongly
dependent on the thickness of seed layer, but there was no dependence on deposition temperature of the seed layer. For a 2
nm seed layer, the dielectric constants were higher by about 29% than those of single-step BST thin films due to higher crystallinity
and the leakage current was nearly the same as that of a single-step sample in bias voltage from −2 to 2.5 V. However, an
improvement of the dielectric constant was not observed for samples having above 4 nm thick seed layers. A 40 nm thick BST
film with 2 nm thick seed layer deposited by a two-step method exhibited a SiO2 equivalent thickness of 0.385 nm and a leakage current density of 2.74 × 10−8A/cm2at+1.5V after post-annealing under an atmosphere of flowing N2 for 30 min at 750°C. 相似文献
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Nanolamination has entered the spotlight as a novel process for fabricating highly dense nanoscale inorganic alloy films. OFET commercialization requires, above all, excellent dielectric properties of gate dielectric layer. Here, we describe the fabrication and characterization of Al–O–Ti (AT) nanolaminate gate dielectric films using a PEALD process, and their OFET applications. The AT films exhibited a very smooth surface (Rq < 0.3 nm), a high dielectric constant (17.8), and a low leakage current (8.6 × 10−9 A/cm2 at 2 MV/cm) compared to single Al2O3 or TiO2 films. Importantly, a 50 nm thick AT film dramatically enhanced the value of μFET (0.96 cm2/V) on a pentacene device, and the high off-current level in a single TiO2 film was effectively reduced. The nanolamination process removes the drawbacks inherent in each single layer so that the AT film provides excellent dielectric properties suitable for fabricating high-performance OFETs. Triethylsilylethynyl anthradithiophene (TES-ADT), a solution-processable semiconductor, was combined with the AT film in an OFET, and the electrical properties of the device were characterized. The excellent dielectric properties of the AT film render nanolamination a powerful strategy for practical OFET applications. 相似文献
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J. Tardy M. Erouel A.L. Deman A. Gagnaire V. Teodorescu M.G. Blanchin B. Canut A. Barau M. Zaharescu 《Microelectronics Reliability》2007,47(2-3):372-377
We report here on pentacene based organic field effect transistors (OFETs) with a high-k HfO2 gate oxide. HfO2 layers were prepared by two different methods: anodic oxidation and sol–gel. A comparison of the two processes on the electrical properties of OFETs is given. Ultra thin nanoporous (20 nm) sol–gel deposited oxide films were obtained following an annealing at 450 °C. They lead to high mobility and stable devices (μ = 0.12 cm2/V s). On the other hand, devices with anodic HfO2 revealed a little bit more leaky and show some hysteresis. Anodization, however, presents the advantage of being a fully room temperature process, compatible with plastic substrates. Stability and response to a bias stress are also reported. 相似文献
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P. D. Ye G. D. Wilk B. Yang J. Kwo H. -J. L. Gossmann M. Frei J. P. Mannaerts M. Sergent M. Hong K. K. Ng J. Bude 《Journal of Electronic Materials》2004,33(8):912-915
We demonstrate GaAs-based, metal-oxide-semiconductor field-effect transistors (MOSFETs) with excellent performance using an
Al2O3 gate dielectric, deposited by atomic layer deposition (ALD). This achievement is very significant because Al2O3 possesses highly desirable physical and electrical properties as a gate dielectric. These MOSFET devices exhibit extremely
low gate-leakage current, high transconductance, and high dielectric breakdown strength. A short-circuit, current-gain, cutoff
frequency (fT) of 14 GHz and a maximum oscillation frequency (fmax) of 25.2 GHz have been achieved from a 0.65-μm gate-length device. The interface trap density (Dit) of Al2O3/GaAs is evaluated by the hysteresis of drain-source current, Ids, versus gate-source bias, Vgs, and the frequency dispersion of transconductance, gm. 相似文献
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J.M. Wang 《Microelectronic Engineering》2008,85(9):1920-1923
Lead-magnesium niobate-lead titanate (PMN-PT) thin films with and without the TiO2 seed layer were deposited on Pt/Ti/SiO2/Si substrates through pulsed laser deposition. The study aimed to characterize the effect of the TiO2 seed layer on the phase composition and properties of PMN-PT film. Without the TiO2 seed layer, the pure perovskite phase could be obtained in the thinner PMN-PT film while with the TiO2 seed layer, the pure perovskite phase was formed in the thicker PMN-PT film. The ferroelectric properties of PMN-PT films with the TiO2 seed layer were exhibited. As a result, the maximum amount of remnant polarization reached the amount of 32 μC/cm2 for the PMN-PT thin film with the TiO2 seed layer. 相似文献
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Ba6−3xNd8+2xTi18O54 with x=0.25 (BNT-0.25, or simply, BNT) dielectric thin films with a thickness of 320 nm have been prepared on Pt-coated silicon
substrates by pulsed laser deposition (PLD) at the substrate temperature of 650°C in 20 Pa oxygen ambient. X-ray analysis
showed that the as-deposited films are amorphous and the films remain amorphous after a postannealing at 750°C for 30 min.
The dielectric constant of the BNT films has been determined to be about 80 with a low loss tan δ of about 0.006 at 1 MHz.
The capacitance-voltage (C-V), capacitance-frequency, and capacitance-temperature characteristics of a BNT capacitor with
Pt top electrode were measured. A low leakage-current density of 4×10−6 A/cm2 at 6 V was measured, and a preliminary discussion of the leakage-current mechanism is also given. It is proposed that amorphous
BNT-0.25 thin films will be a potential dielectric material for microwave applications. 相似文献