过滤电弧沉积非晶金刚石薄膜的光谱椭偏研究

为了深入理解过滤阴极电弧沉积非晶金刚石薄膜的光学性质,利用光谱椭偏仪研究了薄膜光学常数随测试偏振光波长变化的谱学关系,进而分析了薄膜折射率、消光系数和光学带隙与沉积能量之间的变化规律。实验表明,非晶金刚石薄膜的折射率高于金刚石晶体的折射率,薄膜的吸收光谱在高吸收区可以用抛物线型函数描述,并由此计算Tauc带隙。随着波长向红外延伸,非晶金刚石薄膜的消光系数渐次降低并趋近于零,光学常数因沉积能量变化而实现的调整幅度也逐渐缩小。随着衬底偏压的增加,折射率和光学带隙都是先升高后减小,并在负偏压为80 V时有最大值;而消光系数却是先减小再升高,在负偏压为80 V时有最小值。     

脉冲偏压电弧离子镀TiO2薄膜的力学与光学性能

用脉冲偏压电弧离子镀技术在玻璃基片上制备均匀透明的TiO₂薄膜.利用X射线衍射仪、原子力显微镜、扫描电子显微镜、紫外-可见透射光谱仪和纳米压痕仪等手段,对不同脉冲负偏压下合成薄膜的相结构、微观结构、表面形貌、力学和光学性能进行表征.结果表明，沉积态薄膜为非晶态.脉冲负偏压对薄膜性能有明显的影响.随偏压的增加，薄膜厚度、硬度和弹性模量均先增大后减小，前者峰值出现在100—200 V负偏压范围，后两者则在250—350V范围.300 V负偏压时薄膜硬度最高，薄膜达到原子级表面光滑度，均方 关键词： 2薄膜')" href="#">TiO₂薄膜 脉冲偏压电弧离子镀 硬度 折射率     

负偏压对磁控溅射Ti膜沉积速率和表面形貌的影响

 采用直流磁控溅射加负偏压的方法制备了Ti膜,研究了不同偏压条件对Ti膜沉积速率、密度、生长方式及表面形貌的影响。随着偏压逐渐增大,Ti膜沉积速率分三个阶段变化:0~ -40 V之间沉积速率基本不变; -40~ -80 V之间沉积速率迅速降低;超过-80 V后沉积速率随偏压的下降速度又放缓。Ti膜密度随偏压增加而增大,负偏压为-119.1 V时开始饱和并趋于块体Ti材密度。加负偏压能够抑制Ti膜的柱状生长方式;偏压可以改善Ti膜的表面形貌,对于40 W和100 W的溅射功率,负偏压分别在-100 V和-80 V左右时制备出表面光洁性能较佳的Ti膜。     

非晶金刚石薄膜的X射线反射研究

利用过滤阴极真空电弧系统制备了不同衬底偏压下非晶金刚石薄膜,分别采用X射线反射法测定了相应的非晶金刚石膜密度,分析了薄膜密度与沉积能量之间的变化规律．建立了薄膜密度随衬底偏压的变化曲线。研究发现在-80V时非晶金刚石膜密度存在最大值3．26g／cm^2,随着偏压的增大和减小,薄膜的密度都相应的下降;当衬底偏压加到-2000V时,密度减小到2．63g／cm^2,相对于密度的最大值变化较小。通过薄膜sp^3能态杂化含量与密度的简单比例关系,近似推算出非晶金刚石膜中sp^3能态的含量最高可达80％以上。     

常温溅射DLC膜的工艺研究

常温下,采用磁控溅射技术成功地在Ge基底上制备了类金刚石膜,并研究了溅射功率、碳氢气体与氩气流量比、溅射频率、基底负偏压等工艺参数对类金刚石膜沉积速率的影响和薄膜的光学性能。结果表明：溅射功率、溅射频率、碳氢气体与氩气流量比对沉积速率有显著的影响。沉积速率随着溅射功率的增大而增大,随着溅射频率的减小而增大。随着碳氢气体与氩气流量比、基底负偏压的增大沉积速率先增大后降低。制备的类金刚石膜具有较宽的光谱透明区,Ge基底单面沉积的类金刚石膜其峰值透过率最高达到63．99％。     

脉冲直流偏压增强的高质量立方氮化硼薄膜的合成

采用磁增强活性反应离子镀系统成功地合成了立方氮化硼薄膜.通过给基片施加脉冲直流偏压以代替传统的射频偏压,增强了立方氮化硼的成膜稳定性,研究了基片的直流脉冲偏压、等离子体放电电流、通入气体流量比(Ar/N₂)和基片温度沉积参数对立方氮化硼薄膜形成的影响规律.结果表明:随着基片负偏压和放电电流的增大,薄膜中立方氮化硼的纯度提高,当基片负偏压为155V,放电电流为15A时,可获得几乎单相的立方氮化硼薄膜.基片温度为500℃和Ar/N₂流量比为10时,最有利于立方氮化硼 关键词： 立方氮化硼 活性反应离子镀 脉冲偏压     

离子束反应溅射沉积SiO2薄膜的光学特性

 主要研究采用离子束反应溅射（RIBS）制备SiO2薄膜的折射率、消光系数、化学计量比与氧气在氩氧混合工作气体中含量及其沉积速率的关系。研究结果表明：RIBS制备的SiO2薄膜在0.63 μm处折射率n= 1.48,消光系数小于10-5;随着沉积速率的增加,薄膜的折射率和消光系数随之变大,当沉积速率超过0.3 nm/s,即使是在纯氧环境溅射,折射率值也不低于1.5;通过对红外透射光谱的主吸收峰位置研究得到沉积的SiO2薄膜为缺氧型,化学计量比不超过1.8,且红外吸收峰位置和SiO2折射率存在对应关系,因此在不加热衬底情况下使用RIBS制备SiO2薄膜时,会限制沉积速率的提高。     

比较2种溅射方法镀制的氧化硅薄膜

比较了磁控反应溅射(RMS)法与离子束反应溅射(RIBS)法沉积得到的氧化硅薄膜的光学特性,并确定了其对折射率n、消光系数k、沉积速率和混合工作气体Ar/O2中氧含量的依赖性关系。工作气体中O2含量大于15%时通过RMS法沉积的氧化硅薄膜在0.63μm波长折射率约为1.52~1.55,消光系数低于10-5。当O2含量在80%以上时RIBS方法沉积氧化硅薄膜的折射率n=1.52~1.6,消光系数低于10-5。用RMS沉积SiO2薄膜,当氧气量超过15%时发生反应模式,此时沉积速率下降近5倍。而用RIBS时,沉积速率并不依赖氧气在混合工作气体中的含量。     

电子回旋共振-射频双等离子体沉积氧化硅薄膜过程中的射频偏压效应

本文利用六甲基乙硅氧烷(HMDSO)和氧气(O2)为反应气体,利用微波电子回旋共振-射频双等离子体化学气相沉积法沉积氧化硅薄膜,并利用发射光谱对等离子体特性进行原位诊断.研究表明,RF偏压对氧化硅薄膜沉积速率和薄膜中的化学键结构产生有意义的影响.小的直流自偏压会略微提高沉积速率;但随着直流自偏压的增加,离子轰击效应及刻蚀作用加强,薄膜的沉积速率下降.在13.56MHz和400kHz两个不同射频频率条件下所沉积的薄膜中,O和Si的比例基本相同,均超过2∶1;但400kHz射频偏压下薄膜中的碳成分比例比13.56MHz条件下的要高得多.这可以归因为高的射频偏压的应用不仅可增强离子轰击效应,而且与体等离子体相互作用,使高活性的氧原子增多;而低频偏压的作用主要是增强离子轰击效应.     

磁控溅射制备铬薄膜的结构和光电学性质

用直流磁控溅射技术在石英基片上制备不同厚度(5 nm~114 nm之间)的铬膜.使用X射线衍射仪和分光光度计分别检测薄膜的结构和光学性质,利用德鲁特模型和薄膜的透射、反射光谱计算铬膜的厚度和光学常量,并采用Van der Pauw方法测量薄膜电学性质.结果表明:制备的铬薄膜为体心立方的多晶态,随着膜厚的增加,薄膜的结晶性能提高,晶粒尺寸增大;在可见光区域,当膜厚小于32 nm时,随着膜厚的增加,折射率快速减小,消光系数快速增大,当膜厚大于32 nm时,折射率和消光系数均缓慢减小并逐渐趋于稳定;薄膜电阻率随膜厚的增加为一次指数衰减.     

Influence of substrate bias voltage on structure and properties of the CrAlN films deposited by unbalanced magnetron sputtering

The CrAlN films were deposited on silicon and stainless steel substrates by unbalanced magnetron sputtering system. The influence of substrate bias on deposition rate, composition, structure, morphology and properties of the CrAlN films was investigated. The results showed that, with the increase of the substrate bias voltage, the deposition rate decreased accompanied by a change of the preferred orientation of the CrAlN film from (2 2 0) to (2 0 0). The grain size and the average surface roughness of the CrAlN films declined as the bias voltage increases above −100 V. The morphology of the films changed from obviously columnar to dense glass-like structure with the increase of the bias voltage from −50 to −250 V. Meanwhile, the films deposited at moderate bias voltage had better mechanical and tribological properties, while the films deposited at higher bias voltage showed better corrosion resistance. It was found that the corrosion resistance improvement was not only attributed to the low pinhole density of the film, but also to chemical composition of films.     

Effect of nickel on the structure and bond type in amorphous diamond-like carbon films

Experimental data are presented from studies of the structure and bond type of carbon atoms in amorphous carbon-nickel films deposited from pulsed vacuum-arc discharge plasma sources. X-ray photoelectron spectroscopy was used. The characteristics of the plasmon loss spectra depend significantly on the deposition parameters. Carbon exists in a mixed sp²+sp³ hybridized state in the carbon–nickel films. The ratio of sp³/sp² carbon bonds increases when the nickel content is reduced (from 5.5 to 1.0 atomic %) and the deposition angle is increased. The structure closest to that of diamond was with a substrate bias voltage of –80 to –100 V and a deposition angle of 90°.     

Phase transitions in the CN<Subscript>x</Subscript>-TiN system attendant on the variation of the bias voltage during ion-stimulated growth

The structure of amorphous CN_x-TiN films grown by ion-stimulated deposition at a bias voltage U = 200–500 V is studied by X-ray diffraction. As the bias voltage increases in the range U = 300–360 V, the CN_x-TiN films are shown to undergo a phase transition in the amorphous phase having different order scales (20–50 Å): this transition is related to an increase in the content of the fraction of medium-cell (4 Å) carbon clusters as compared to the fractions of clusters with large (8 Å) and small (2 Å) cells. Under these conditions, 80–150 Å crystalline clusters undergo the phase transition from the Ti₂C(N) carbide into graphite (C _g) and diamond (C_d); the last two phases are represented by 100-Å clusters.     

甲烷电离特性的等离子体发射光谱法研究

应用等离子体发射光谱法,用CCD(charge coupled device)光栅光谱仪记录并标识了脉冲电晕甲烷等离子体370～1 100 nm的发射光谱,确定了常温常压下高纯甲烷(99.99%)经100 kV, 100 Hz脉冲高压电离后的产物为H,C+,CH,C,C₂,C₃, C₄,C₅和烃等。通过分析实验检测到的甲烷等离子体发射光谱,给出了甲烷经脉冲高压电离形成电晕等离子体的机理和自由基CH_n(n=3,2,1)、碳、烃等产物的电离途径。结果显示甲烷分子经高能电子非弹性碰撞后脱氢程度很高,大量氢原子及其离子和甲烷自由基在进一步被高能电子作用下合成了烯烃、炔烃、烷烃和高聚碳化物。实验所获得的脉冲甲烷等离子体发射光谱及其机理分析可为甲烷及其转化研究提供相关依据。     

脉冲偏压电弧离子镀Cr-O薄膜结构及光学性能研究

采用脉冲偏压电弧离子镀技术在单晶硅基片及石英玻璃上制备了一系列均匀透明的Cr-O薄膜. 用场发射扫描电子显微镜、X射线衍射仪、X射线光电子谱、纳米压痕仪、紫外可见光分光光度计等方法对薄膜的表面形貌、膜厚、相结构、成分、元素的化学价态、硬度和光学性能等进行表征, 主要研究了偏压幅值对薄膜结构和性能的影响. 结果表明, 施加偏压可使薄膜的沉积质量明显提高, 其相结构由非晶态转变为晶体态, 并随着偏压幅值的增加, 由Cr₂O₃相向CrO相转变; 薄膜的硬度先增大后减小, 当偏压为-300 V时, 硬度达到最大值24.4 GPa; 薄膜具有良好的透光率, 最高可达72%; 当偏压为-200 V时, 薄膜的最大光学帯隙为1.88 eV.     

Effect of DC bias on microstructural rearrangement of a-SiN:H films on PET substrate

Hydrogenated amorphous silicon nitride (a-SiN:H) films were deposited on flexible polyethylene terephthalate substrates at temperature as low as 100 °C by hot-wire chemical vapor deposition using SiH₄, H₂ and NH₃ precursors. Field emission scanning emission microscopy, Raman spectroscopy, Fourier transform infrared spectroscopy and small angle X-ray scattering were employed to study structural and microstructural properties of a-SiN:H films. The rms surface roughness increased with increase of positive bias to substrate. Intermediate range order, porosity and interface inhomogeneity in amorphous of a-SiN:H films evaluated by acoustic and optical phonon of silicon network, Guinier plot and correlated length from Raman and SAXS characterizations. The fractal behavior of a-SiN:H domains approached the perfect symmetry and the intermediate range order of a-SiN:H films deteriorate with increase of the positive substrate bias. Both correlation length and void size of the a-SiN:H amorphous domain increased with increase of the substrate bias from 0 to +200 V.     

脉冲偏压占空比对多孔氧化硅薄膜性质的影响

采用由脉冲负偏压调节的等离子体增强化学气相沉积方法,以硅烷为源气体,在玻璃基片上沉积得到了多孔二氧化硅薄膜。将反应过程中加在沉积区域的脉冲偏压固定在-350V,当占空比从0.162增大到0.864时,薄膜样品的形貌、成份和结构均不相同。扫描电镜照片表明,组成多孔氧化硅薄膜的颗粒在占空比增大时变得细腻,并且薄膜整体变得多孔且蓬松。拉曼光谱和红外光谱结果显示,薄膜样品中的非晶硅和Si-H键在较高的占空比下减弱甚至消失。占空比升高时氧化硅桥键所占比例持续增加。     

A magnetron sputtering technique to prepare a-C:H films: Effect of substrate bias

Amorphous hydrogenated carbon (a-C:H) films were deposited by magnetron sputtering with a mixture gas of Ar and CH₄. The a-C:H films deposited by this method have relatively low internal stress (<1 GPa) compared to some films deposited by conventional deposition process. The effects of substrate bias voltage on microstructure, surface morphology and mechanical properties of the films were investigated by various techniques. It has been found that the polymer-like structure is dominated at low bias voltage (−100 V), while the diamond-like structure with the highest hardness and internal stress is the main feature of the a-C:H films deposited under high bias voltage (−300 V). With increasing the bias voltage further, the feature of diamond-like structure decreases associating with the increase of graphitization. The frictional test shows that the friction coefficient and wear rate of the a-C:H films are depended strongly on structure and mechanical properties, which were ultimately influenced by the deposition method and bias voltage.     

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采用由脉冲负偏压调节的等离子体增强化学气相沉积方法,以硅烷为源气体,在玻璃基片上沉积得到了多孔二氧化硅薄膜。将反应过程中加在沉积区域的脉冲偏压固定在-350V,当占空比从0.162增大到0.864时,薄膜样品的形貌、成份和结构均不相同。扫描电镜照片表明,组成多孔氧化硅薄膜的颗粒在占空比增大时变得细腻,并且薄膜整体变得多孔且蓬松。拉曼光谱和红外光谱结果显示,薄膜样品中的非晶硅和Si-H键在较高的占空比下减弱甚至消失。占空比升高时氧化硅桥键所占比例持续增加。     

Solid state NMR study of carbon bonding in amorphous hydrogenated carbon films

Carbon bonding environments in hydrogenated amorphous carbon films (a-C:H) deposited from an rf-biased methane plasma onto various substrates have been quantified by application of solid state¹³C NMR. A family of films were prepared by systematically varying the substrate bias voltage. Quantitative data on carbon chemistry in these films is required for modeling the impact of structure on mechanical and optical properties. A variety of NMR acquisition pulse sequences have been investigated to determine the conditions under which quantitative¹³C NMR data can be acquired in this system. The results indicate that data acquisition from this material requires different protocols than for the study of polymeric hydrocarbon films. With proper experimental design, NMR is an excellent technique for structural studies of these materials.