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采用等离子体增强化学气相沉积法(PECVD),在单晶硅衬底(100)上成功制备了不同生长工艺条件下的氮化硅薄膜。分别采用XP-2台阶仪、椭圆偏振仪等手段测试了薄膜的厚度、折射率、生长速率等参数。并采用原子力显微镜(AFM)研究了薄膜的表面形貌。结果表明,温度和射频功率是影响薄膜生长速率的主要因素,生长速率变化幅度可以达到230nm/min甚至更高。对于薄膜折射率和成分影响最大的是NH3流量,折射率变化范围可以达到2.7~1.86。分析得出受工艺参数调控的薄膜生长速率对薄膜的性质有重要影响。 相似文献
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为实现氧化物TFT(Indium Gallium Zinc Oxide Thin Film Transistor,IGZO TFT)特性的最优化,采用I-V数据和SEM(Scanning Electron Microscope)图片研究蚀阻挡层(Etch-Stop Layer,ESL)沉积条件与氧化物TFT特性的关系。通过调整沉积温度、正负极板间距、压力和功率,分析了PECVD沉积ESL SiO2的成膜规律,并对所得到的TFT进行了特性分析。发现ESL膜层致密性过差时,后期高温工艺会造成水汽进入IGZO半导体膜层,从而引起TFT特性恶化。而采用高温、高压力等方法取得高致密性的ESL膜层由于高强度等离子体对IGZO本体的还原反应也会致使TFT特性劣化。结果表明,在保证膜层致密性前提下,等离子体对IGZO本体伤害最小的ESL沉积条件才是最优化的ESL沉积条件。 相似文献
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等离子增强化学气相淀积(PECVD)法制备的氮化硅薄膜具有沉积温度低、生长速率高和残余应力可调节等特点,研究其力学特性对研制MEMS器件和系统具有重要意义。采用HQ-2型PECVD淀积台,在沉积温度为350℃,NH3流量为30cm3/min的条件下,通过改变氩气稀释至5%的SiH4流量和射频功率大小,制备了具有压应力、微应力和张应力的多种氮化硅薄膜样品。采用纳米压痕仪Nanoidenter-G200对淀积薄膜的杨氏模量和硬度进行测试,结果表明,在较小的SiH4流量和较高的射频功率条件下,淀积的氮化硅薄膜具有更高的杨氏模量和硬度。 相似文献
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流量及温度对低频PECVD氮化硅薄膜性能的影响 总被引:1,自引:0,他引:1
研究了低频等离子增强化学气相沉积(LF-PECVD)工艺中气体流量比和衬底温度对氮化硅薄膜折射率、密度及应力的影响规律,同时测试了薄膜的红外光谱以分析不同条件对薄膜成分的影响.结果表明,低频氮化硅薄膜折射率主要受薄膜内硅氮元素比的影响,其次是薄膜密度的影响.前者主要由硅烷/氨气反应气体流量比决定,而后者主要由衬底温度决定;低频氮化硅薄膜应力大致与密度成正比关系.此外,PECVD工艺所制备氮化硅薄膜都含有相当数量的氢元素,而衬底温度是薄膜内氢含量的决定因素. 相似文献
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Tang Longjuan Zhu Yinfang Yang Jinling Li Yan Zhou Wei Xie Jing Liu Yunfei Yang Fuhua 《半导体学报》2009,30(9):096005-096005-4
tchants for SiO2 and SiNx:H. A high etching selectivity of SiO2 over SiNx:H was obtained using highly concentrated buffered HE 相似文献
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本文对氮化硅的增强电容耦合等离子刻蚀进行研究,为氮化硅刻蚀工艺的优化提供参考。针对SF_6+O_2气体体系,通过设计实验考察了功率、压强、气体比、氦气等对刻蚀速率和均一性的影响,并对结果进行机理分析和讨论。实验结果表明:功率越大,刻蚀速率越大,与源极射频电力相比,偏置射频电力对刻蚀速率的影响更为显著;压强增大,刻蚀速率增大,但压强增大到一定程度后,刻蚀速率基本不变,刻蚀均匀性随着压强增大而变差;在保证SF_6/O_2总流量保持不变下,O_2的比例增大,刻蚀速率先增大后减小,刻蚀均匀性逐步变好;He的添加可以改善刻蚀均匀性,但He的添加量过多时,会造成刻蚀速率降低。 相似文献
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W. Hu Florence Y. M. Chan D. P. Webb Y. C. Chan Y. W. Lam 《Journal of Electronic Materials》1996,25(12):1837-1840
The optical properties of hydrogenated amorphous silicon thin films prepared by a new thermocatalytic plasma enhanced chemical
vapor deposition (PECVD) method are here reported for the first time. The transmission spectrum of the film, deposited at
a rate of 1.5 nm/s, was measured between 500 and 1100 nm. The envelopes of the transmission spectrum interference maxima and
minima were analyzed to reveal the absorption coefficient α(λ@#@), the refractive indexn(λ), the average thickness of the film (791 nm) and the variation of the thickness (11.4 nm), using an analysis which takes into
account film inhomogeneity. The modified Newton's method of numerical analysis was used to obtain the optical parameters.
The optical band gap ε0} was determined to be 1.69 eV from the absorption coefficient spectrum, commensurate with values quoted for lower deposition
rate PECVD films. The value for ε0}, the small variation of the film thickness, and a value for the defect density of 3.7 x 1015}cm-3} determined for similar material in other work indicate that the thermocatalytic PECVD method can produce acceptable quality
films at a high deposition rate. 相似文献
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Physical properties of memory quality PECVD silicon nitride 总被引:1,自引:0,他引:1
M. A. Khaliq Q. A. Shams W. D. Brown H. A. Naseem 《Journal of Electronic Materials》1988,17(5):355-359
Memory-quality silicon nitride has been deposited using plasma-enhanced chemical vapor deposition (PECVD). Film composition
was varied by controlling the nitrogen concentration of the reactant gases. The effects of the source and content of the nitriding
agent on the physical properties of the film were studied using ellipsometry and ultraviolet (UV), fourier transform infrared
(FTIR) and Auger electron spectroscopy. Refractive index of the films varied from 1.77 to 1.95 corresponding to Si/N ratios
of 0.75 to 1.03. Ultraviolet spectroscopy yielded band edge values of 4.9 to 2.2 eV depending on the Si/N ratio. Window size,
endurance and retention performance is comparable to that reported for both atmospheric- and low-pressure chemical vapor deposited
films. A strong correlation between the Si-H bond concentration and the memory performance was observed. Although some excess
silicon in the film is needed for memory operation in a metal-nitride-oxide-silicon (MNOS) structure, excessive amounts result
in low breakdown fields, small memory windows and poor retention characteristics.
This work was supported by a grant from the National Science Foundation. 相似文献
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《Microelectronics Journal》2004,35(1):65-67
In this work optical properties of SiOX (0<X<2) layers obtained by plasma enhanced chemical vapor deposition are studied. Infrared spectra and refractive index dependences with the reactant gases flow ratio R are explained for as deposited, aged and thermally treated samples in the R range from 9.17 to 110. Variations are found to be influenced mainly by sample stoichiometry, density and Si-OH bonds concentration. 相似文献
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Donald L. Smith Andrew S. Alimonda Chau-Chen Chen Hsing C. Tuan 《Journal of Electronic Materials》1990,19(1):19-27
The high rate of charge trapping in thin-film silicon nitride causes its electrical properties to change with stressing level
and time. The rate of shift of the high-frequency CV curves of Al/SiNxHy/cSi capacitors was used here to measure nitride charging rate and to compare PECVD nitrides deposited under various conditions
of plasma power and gas mixture in the same parallel-plate reactor. By operating the plasma under high power to activate the
NH3 or N2 and under low SiH4 flow to ensure that all of the SiH4 reacts with N, it is possible to deposit N-rich nitride that has no detectable Si—H bonding,
which bonding others have correlated with charge trapping. Nitride deposited under these conditions using NH3 and 13 MHz rf power had charging rates for both gate polarities that were 20 times lower than those of nitride that had a
“stoichiometric” N/Si ratio of 4/3 and that had its H distributed among Si—H and N—H bonds. MIS capacitors made with the latter
nitride also had a high negative initial flat-bond voltage, indicating the presence of grown-in positive charge. This charge
was large enough to invert the surface ofp-Si substrates. N-rich nitride free of Si—H that was deposited either using N2 or using low-frequency rf power (≤400 kHz) had higher charging rates than did that deposited from NH3 at 13 MHz. Also, the low-frequency material contained grown-in positive charge that is attributed to H+ implanted by the high ion bombardment energy of the low-frequency plasma. 相似文献
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二维流体模型的建立及其在微晶硅薄膜中的应用 总被引:1,自引:0,他引:1
建立二维流体模型,研究甚高频等离子体化学气相沉积(VHF-PEVCVD)高速沉积氢化微晶硅(μc-Si:H)薄膜.模型采用平行电容耦合放电方式. 模拟条件与实验条件相同,均为甚高频(70 MHz)、高H2稀释SiH4和高压耗尽区域.模型的几何结构是根据实际高速沉积μc-Si:H薄膜的反应腔室建立的.模型是自适应的,建立在玻尔兹曼方程和泊松方程基础之上,包含87个气相反应和25个表面反应.将模拟沉积速率与相同实验条件下的结果相比较,结果发现,模型在微晶区域运行结果与实验结果吻合得很好. 相似文献
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B. Anthony T. Hsu L. Breaux R. Qian S. Banerjee A. Tasch 《Journal of Electronic Materials》1990,19(10):1089-1094
The reaction kinetics in Remote Plasma-enhanced Chemical Vapor Deposition (RPCVD) have been studied for a chamber pressure
of 200 mTorr, rf powers between 4 and 8 W, diluted silane flow rates between 5 and 40 sccm, and temperatures between 190 and
480° C. The observed temperature dependence of growth rate reveals a change in activation energy at 300–325° C, suggesting
that hydrogen desorption is the rate limiting step in the deposition reaction. A strong dependence of growth rate on rf power
has been attributed in part to the extension of the glow discharge region closer to the substrate at higher rf powers. Growth
rate has been shown to increase when the sample is positioned closer to the glow, indicating that the reaction precursor is
a short-lived species, probably SiH2 or SiH3. Growth rate has been shown to exhibit a sublinear dependence on silane partial pressure. Oxygen incorporation in the deposited
films has been studied using Secondary Ion Mass Spectroscopy (SIMS), and it has been found that the main source of oxygen
contamination is the process gases. However, it has also been found that “point of use” purification of the process gases
reduces water and oxygen contamination significantly, reducing the oxygen incorporation in the films by an order of magnitude. 相似文献
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A thin film encapsulation layer was fabricated through two-sequential chemical vapor deposition processes for organic light emitting diodes (OLEDs). The fabrication process consists of laser assisted chemical vapor deposition (LACVD) for the first silicon nitride layer and laser assisted plasma enhanced chemical vapor deposition (LAPECVD) for the second silicon nitride layer. While SiNx thin films fabricated by LAPECVD exhibits remarkable encapsulation characteristics, OLEDs underneath the encapsulation layer risk being damaged during the plasma generation process. In order to prevent damage from the plasma, LACVD was completed prior to the LAPECVD as a buffer layer so that the laser during LACVD did not damage the devices because there was no direct irradiation to the surface. This two-step thin film encapsulation was performed sequentially in one chamber, which reduced the process steps and increased fabrication time. The encapsulation was demonstrated on green phosphorescent OLEDs with I–V-L measurements and a lifetime test. The two-step encapsulation process alleviated the damage on the devices by 19.5% in external quantum efficiency compared to the single layer fabricated by plasma enhanced chemical vapor deposition. The lifetime was increased 3.59 times compared to the device without encapsulation. The composition of the SiNx thin films was analyzed through Fourier-transform infrared spectroscopy (FTIR). While the atomic bond in the layer fabricated by LACVD was too weak to be used in encapsulation, the layer fabricated by the two-step encapsulation did not reveal a Si–O bonding peak but did show a Si–N peak with strong atomic bonding. 相似文献