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The poly-Si thin film was obtained by electric field-enhanced metal-induced lateral crystallization technique at low temperature. Raman spectra, X-ray diffraction (XRD) and scan electron microscope (SEM) were used to analyze the crystallization state, crystal structure and surface morphology of the poly-Si thin film. Results show that the poly-Si has good crystallinity, and the electric field has the effect of enhancing the crystallization when DC electric voltage is added to the film during annealing. Secondary ion mass spectroscopy (SIMS) shows that the metal Ni improves the crystallization by diffusing into the a-Si thin film, so the crystallization of the lateral diffused region of Ni is the best. The p-channel poly-Si thin film transistors (TFTs) were fabricated by this large-size grain technique. The IDS−VDS and the transfer characteristics of the TFTs were measured, from which, the hole mobility of TFTs was 65 cm2/V s, the on and off current ratio was 5×106. It is a promising method to fabricate high-performance poly-Si TFTs at low temperature for applications in AMLCD and AMOLED. 相似文献
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In this paper, a new hydrogenation process of poly-Si thin film for the fabrication of poly-Si thin film transistors (TFTs) is proposed. In the new approach, the hydrogenation of TFTs is performed before deposition of contact metal. N-channel and p-channel poly-Si TFTs with various channel lengths and widths were fabricated with the new and conventional processes for comparison. The results verified that the efficiency of hydrogenation has been improved remarkably by the new process. The field-effect mobility of carriers, the on state current, threshold voltage and the on/off states current ratio have been greatly improved, and the trap state density has been reduced significantly. 相似文献
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We have developed a low-temperature fabrication process (⩽ 200°C for high-quality polycrystalline Si thin-film transistors (poly-Si TFTs) on flexible stainless-steel foils. The fabrication processes is realized through sputter deposition of thin films, including active-Si and gate-SiO2 films, crystallization of Si films by KrF excimer laser irradiation, and inductively coupled plasma hydrogenation. High-quality n- and p-channel poly-Si TFTs are successfully fabricated without suffering from problems of substrate bending, film ablation, or cracking in films. The resulting n- and p-channel poly-Si TFTs showed mobilities of 106 and 122 cm2/V·s, respectively. This paper describes the deposition and properties of the sputtered Si films and the fabrication process and electrical characteristics of the poly-SiTFTs 相似文献
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Jae-Hong Jeon Min-Cheol Lee Kee-Chan Park Min-Koo Han 《Electron Device Letters, IEEE》2001,22(9):429-431
A new excimer laser annealing method, which results in large lateral polysilicon grains exceeding 1.5 μm, has been proposed and polycrystalline silicon thin film transistors (poly-Si TFTs) with a single grain boundary in the channel have been successfully fabricated. The proposed method employs a lateral grain growth phenomenon obtained by excimer laser irradiation on an amorphous silicon layer with pre-patterned aluminum film. The aluminum patterns act as a masking layer of the incident laser beam for the selective melting of the amorphous silicon layer. Uniform and large grains are obtained near the edge of the aluminum patterns. When two aluminum patterns are separated by a 2 μm space, the solidified region (i.e., poly-Si channel) exhibits a single grain boundary. The n-channel poly-Si TPT fabricated by the proposed method shows considerably improved I-V characteristics, such as high field effect mobility exceeding 240 cm2/Vs 相似文献
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多晶硅薄膜晶体管的表面氮钝化技术 总被引:2,自引:0,他引:2
采用N2O和NH3等离子钝化技术对多晶硅薄膜表面和栅氧表面进行了钝化处理。实验结果表明,该技术能有效降低多晶硅薄膜的界面态密度,提高多晶硅薄膜晶体管性能,二次离子质谱分析表明在p-Si/SiO界面有氮原子富积,说明生成了强的Si-N键。 相似文献
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A high-performance polycrystalline silicon thin film transistorwith a silicon nitride gate insulator
We have fabricated a high performance polycrystalline silicon (poly-Si) thin film transistor (TFT) with a silicon-nitride (SiNx ) gate insulator using three stacked layers: very thin laser of hydrogenated amorphous silicon (a-Si:H), SiNx and laser annealed poly-Si. After patterning thin a-Si:H/SiNx layers, gate, and source/drain regions were ion-doped and then Ni layer was deposited. This structure was annealed at 250°C to form a NiSi silicide phase. The low resistive Ni silicides were introduced as gate/source/drain electrodes in order to reduce the process steps. The poly-Si with a grain size of 250 nm and low resistance n+ poly-Si for ohmic contact were introduced to achieve a high performance TFT. The fabricated poly-Si TFT exhibited a field effect mobility of 262 cm2/Vs and a threshold voltage of 1 V 相似文献
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L. Mariucci A. Pecora S. Giovannini R. Carluccio F. Massussi G. Fortunato 《Microelectronics Reliability》1999,39(1):45
Hot-carrier effects on both the electrical characteristics and the noise performance in polycrystalline silicon thin film transistors are analysed. The devices were fabricated by using a combined solid phase crystallization (SPC) and excimer laser annealing (ELA) process, combining the beneficial aspects of the two techniques. Hot-carrier degradation results in the formation of both interface states, which have been evaluated through the analysis of the sheet conductance and of oxide traps near the insulator/semiconductor interface, as evidenced by the 1/f noise measurements. Oxide traps are calculated evaluating the flat band voltage spectral density associated with interface charge fluctuations in the damaged part of the interface. A strong correlation between interface state and oxide trap densities has been found, suggesting a common origin for the generation mechanism of the two types of defects. 相似文献
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RAO Rui XU Chong-yang SUN Guo-cai ZHOU Xue-mei ZENG Xiang-bin ZHAO Bo-fang 《半导体光子学与技术》2001,7(1):17-19,23
Using a new low-temperature process (<600 ℃), the poly-Si TFT was fabricated by metal-induced lateral crystallization (MILC). An ultrathin aluminum layer was deposited on a-Si film and selectively formed by photolithography. The films were then annealed at 560 ℃ to obtain laterally crystallized poly-Si film, which is used as the channel area of a TFT. The poly-Si TFT showed an on/off current ratio of higher than 1×10 6 at a drain voltage of 5 V. The electrical properties are much better than TFT fabricated by conventional crystallization at 600 ℃. 相似文献
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Seok-Woon Lee Seung-Ki Joo 《Electron Device Letters, IEEE》1996,17(4):160-162
A new low temperature crystallization method for poly-Si TFTs was developed: Metal-Induced Lateral Crystallization (MILC). The a-Si film in the channel area of a TFT was laterally crystallized from the source/drain area, on which an ultrathin nickel layer was deposited before annealing. The a-channel poly-Si TFTs fabricated at 500°C by MILC showed a mobility of 121 cm2/V·s, a threshold voltage of 1.2 V, and an on/off current ratio of higher than 106 . These electrical properties are much better than TFTs fabricated by conventional crystallization at 600°C 相似文献
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Min Cao Talwar S. Kramer K.J. Sigmon T.W. Saraswat K.C. 《Electron Devices, IEEE Transactions on》1996,43(4):561-567
A high-performance polysilicon thin-film transistor (TFT) fabricated using XeCl excimer laser crystallization of pre-patterned amorphous Si films is presented. The enhanced TFT performance over previous reported results is attributed to pre-patterning before laser crystallization leading to enhanced lateral grain growth. Device performance has been systematically investigated as a function of the laser energy density, the repetition rate, and the number of laser shots. Under the optimal laser energy density, poly-Si TFT's fabricated using a simple low- temperature (⩽600°C) process have field-effect mobilities of 91 cm2/V·s (electrons) and 55 cm2/V·s (holes), and ON/OFF current ratios over 10 7 at VDs=10 V. The excellent overall TFT performance is achieved without substrate heating during laser crystallization and without hydrogenation. The results also show that poly-Si TFT performance is not sensitive to the laser repetition rate and the number of laser shots above 10 相似文献
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为了研究连续激光晶化非晶硅薄膜中激光功率密度对晶化效果的影响,利用磁控溅射法制备非晶硅薄膜,采用连续氩氪混合离子激光器对薄膜进行退火晶化,用显微喇曼光谱测试技术和场发射扫描电子显微镜研究了薄膜在5ms固定时间下不同激光功率密度对晶化效果的影响,并对比了普通玻璃片和石英玻璃两种衬底上薄膜晶化过程的差异。结果表明,在一定激光功率密度范围内(0kW/cm2~27.1kW/cm2),当激光功率密度大于15.1kW/cm2时,普通玻璃衬底沉积的非晶硅薄膜开始实现晶化;随着激光功率密度的增大,晶化效果先逐渐变好,之后变差;激光功率密度增大到24.9kW/cm2时,薄膜表面呈现大面积散落的苹果状多晶硅颗粒,晶粒截面尺寸高达478nm ;激光功率密度存在一个中间值,使得晶化效果达到最佳;石英衬底上沉积的非晶硅薄膜则呈现与前者不同的结晶生长过程,当激光功率密度为19.7kW/cm2时,薄膜表面呈现大晶粒尺寸的球形多晶硅颗粒,并且晶粒尺寸随着激光功率密度的增大而增大,在 27.1kW/cm2处晶粒尺寸达到最大5.38m。研究结果对用连续激光晶化法制备多晶硅薄膜的研究具有积极意义。 相似文献
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High-mobility poly-Si thin-film transistors (TFTs) were fabricated by a novel excimer laser crystallization method based on dual-beam irradiation. The new method can reduce the solidification velocity of the top Si layer by heating the bottom Si layer of the Si/SiO2/Si/glass substrate structure by means of laser irradiation not only from the front side but also from the back side. The grain size of poly-Si film was enlarged up to 2 μm. The field-effect mobilities of the TFT exceeded 380 cm2/V-s for electrons and 100 cm2/V-s for holes 相似文献
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The metal-induced crystallization of poly-Si and the mobility enhancement of thin film transistors fabricated on a glass substrate 总被引:1,自引:0,他引:1
In this study, we report on the fabrication of poly-crystalline silicon (poly-Si) using the metal-induced crystallization (MIC) method and its application to thin film transistors (TFTs). The top gate of the p-type TFTs, whose active layer used MIC poly-Si annealed for 1 h at 650 °C, showed a field effect mobility (μFE) of 7.5 cm2/V s. By increasing the crystallization time to 5 h, the quality of the MIC poly-Si was improved. The μFE increased from 7.5 to 15 cm2/V s. In order to enhance the channel mobility, the Si dangling bonds, which were produced during the transformation from the amorphous phase to the poly-crystalline phase of silicon (Si), were reduced by using plasma hydrogenation. Measurements show that the μFE reached 45 cm2/V s after passivation by an inductively coupled plasma chemical vapor deposition (ICPCVD) system. 相似文献
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WANGYu-jiang LIURui-tang 《半导体光子学与技术》2000,6(1):20-22
The electroluminescence thin films doped with erbium, fabricated by thermal evaporation with two boats, are analyzed by X-ray diffraction(XRD).The relationship between electroluminescence brightness and microstructure of the thin films is obtained.The results reveal that the large grain size in high index plane of deposited microcrystalline film has an effect on electroluminescence characteristics of the film devices. 相似文献