质谱分析技术在微波管生产中的应用

一、引言 近年来,由于固体电子器件的迅速发展,在很多方面取代了电真空器件。迫使微波电子管向着大功率、长寿命、低噪声、宽频带、高可靠的方向发展。由此对微波器件的设计、材料、工艺和结构都提出了格外苛刻的要求。为了控制管内残气,改善真空环境,可提高真空度减少和限制有害气体对阴极和器件的危害,但同时也消除了某些气体成份对阴极和器件性能有益的作用,而且真空度太高也会引起许多新的问题。因此在一定真空度下,提高真空环境的质量应引起我们足够的重视。 微波器件中阴极是最娇嫩的部件,电子发射是表面现象,表面是最易污染的,必须千…     

新型力平衡微机械真空传感器研究

力平衡微机械真空传感器采用 ｐ＋＋硅自停止腐蚀技术和硅／玻璃键合技术制作,为了保持参考腔处在高真空状态,使用非蒸散吸气剂来吸附参考腔中的残余气体。研制了两种结构新型力平衡真空传感器,结果表明,采用力平衡模式工作可以扩展传感器的动态范围,灵敏度高。对力平衡电压与真空度的关系进行了研究,理论值与实测值符合得非常好。     

新型力平衡微机械真空传感器研究

力平衡微机械真空传感器采用ｐ＾＋＋硅自停止腐蚀技术和硅／玻璃键合技术制作,为了保持参考腔处在高真空状态,使用非蒸散吸气剂来吸附参考腔中的残余气体。研制了两种结构新型力平衡真空传感器,结果表明,采用力平衡模式工作可以扩展传感器的动态范围,灵敏度高。对力平衡电压与真空度的关系进行了研究,理论值与实测值符合得非常好。     

四极质谱在漂移管直线加速器上的应用

真空检漏是漂移管直线加速器(DTL)获得高真空的重要技术。四极质谱计是分析真空系统内残余气体成分的重要工具,同时也可作为一种检漏手段。本文利用氦质谱检漏仪和四极质谱计两种手段对DTL1~#腔进行检漏。当对12~#漂移管的线圈加电时,腔体内的真空度、漏率和残余气体成分都发生了变化,并且水的谱峰增加最显著,所以判断12#漂移管出现了问题。通过恰当的处理,使腔体很快获得了10~(-6)Pa的高真空,满足了直线加速器对真空系统的要求。     

金属诱导生长多晶锗硅薄膜的电学性能研究

采用超高真空化学气相沉积与金属诱导相结合的方法生长多晶SiGe薄膜。530℃下,金属Ni先与SiGe反应生成Ni硅化物,直至Ni被完全消耗完,接着多晶SiGe薄膜在Ni硅化物上异质生长;首次制作了Al/PolySiGe/Ni Silicide肖特基二极管,对器件的I-V特性测试表明,采用这种结构制备的肖特基结在±1 V时,整流比可达到8 000,而在-2 V时反向漏电流只有10-7A,显示出很好的器件性能。     

兰州重离子冷却储存环（HIREF—CSR）超高真空系统

为了减少真空系统中残余气体分子对离子束造成的损失,要求重离子冷却储存环的平均工作真空度达到3×10     

电真空用金属零件的去油方法

组成电真空器件的金属零件在机加等过程中表面要沾污到一些油污,如果零件没有得到有效的去油清洗,带有残留污染物的零件装配到高真空环境中,可能成为大量气体和蒸气的来源,影响器件的真空度和使用寿命.结合零件表面油污种类、特性,对两种去油方法进行对比:通过洁净度测试、真空热处理和XPS表面残留分析测试结果,说明含活性剂成分的水基清洗液对表面沾污皂化油和非皂化油类的零件清洗效果好,安全无残留,适合高要求的电真空金属零件的去油清洗.     

气相色谱法分析高纯气体的几个问题

前言随着新技木的发展,各领域对高纯气体的品种和质量要求愈来愈高,半导体微电子器件工业,电真空材料加工,各种金属的冶炼和处理,大规模集成电路的研究和生产,色谱等精密仪器用的载气、零点气、标准气的制备,金属有机化合物的合成,石油化     

热丝化学气相沉积(H FCVD)在铜箔上制备双层石墨烯薄膜的研究

双层石墨烯独特的物理性能和特性使其在电子领域拥有广阔的应用前景,引起了学者的广泛关注。采用热丝化学气相沉积方法(HFCVD)在1 cm×2 cm的铜箔上制备石墨烯薄膜,并通过探究腔内气压、基体温度、沉积时间、碳源浓度对石墨烯层数和质量的影响,开发出制备低缺陷双层石墨烯的工艺。采用拉曼光谱仪、扫描电子显微镜和原子力显微镜对石墨烯涂层的结构特征、表面形貌和层数进行了表征。实验结果表明,在铜箔上制备出了均匀致密的低缺陷双层石墨烯,厚度为1.5 nm。此外研究结果还表明,降低腔内气压可减少缺陷和层数,增加基体温度可减少层数,沉积时间4 min或碳源浓度高于1%则无石墨烯生成。因此通过控制腔内气压、基体温度、沉积时间和碳源浓度可实现石墨烯可控生长。     

非蒸散型锆-铝16合金消气剂的研制及在电真空工业中的应用

前言 消气剂是一种装在电真空器件内用来吸收管子封离后的残余气体,以及吸收管子工作时放出的气体的材料。它是电真空器件中的重要部件,对于提高管内真空度,延长寿命及高度可靠的工作起着重要的作用。 消气剂分为蒸散型和非蒸散型二种。蒸散型消气剂是利用蒸散或阴极真空喷镀而生成薄膜镜面用以吸附气体。属于这类消气剂的有Ba-Al,Ba-Ti,Ba-Mg,Ba-N,Ba—Al—Ni等。非蒸散型消气剂是一种容积消气剂,通过整个容积的化学吸附来吸收气体,使用时必须激活才能有效吸气。属于这类消气剂的有Zr—Al,Zr—Ti,Zr—C等合金。其中以Zr—Al合金应…     

Influence of hydrogen on the mechanical properties and microstructure of DLC films synthesized by r.f.-PECVD

This paper aims to investigate the influence of hydrogen on the variation of mechanical properties and microstructure of diamond-like carbon (DLC) films synthesized by radio frequency plasma chemical vapor deposition (r.f.-PECVD). The DLC films were deposited on a silicon substrate (p-type). The reactant gases employed in this paper are a mixture of acetylene and hydrogen. The ratio of hydrogen in the gas mixture was successively varied to clarify its influence on the roughness, thickness, microstructure, hardness, modulus, residual stress and wear depth for the DLC films. The results reveal that increasing the concentration of hydrogen decreases thickness and roughness. Meanwhile, increasing the hydrogen concentration causes the decrease of sp³ ratio, hardness as well as modulus. Finally, wear behavior is correlated to the surface morphology and hydrogen concentration for deposition with hydrogen-containing reactant gas.     

Diffusion and adhesion properties of Cu films on polyimide substrates

Copper thin films were prepared on polyimide (PI) substrates by physical vapor deposition (PVD) and chemical vapor deposition (CVD). Titanium nitride (TiN) diffusion barrier layers were deposited between the copper films and the PI substrates by PVD. Auger electron spectroscopy compositional depth profile showed that TiN barrier layer was very effective in preventing copper diffusion into PI substrate even after the Cu/TiN/PI samples were annealed at 300 °C for 5 h. For the as-deposited CVD-Cu/PI, CVD-Cu/TiN/PI, and as-deposited PVD-Cu/PI samples, the residual stress in Cu films was very small. Relatively larger residual stress existed in Cu films for PVD-Cu/TiN/PI samples. For PVD-Cu/TiN/PI samples, annealing can increase the peeling strength to the level observed without a diffusion barrier. The adhesion improvement of Cu films by annealing treatment can be attributed to lowering of the residual tensile stress in Cu films.     

Thin molybdenum oxide films produced by molybdenum pentacarbonyl 1-methylbutylisonitrile with plasma-assisted chemical vapor deposition

Molybdenum oxide thin films were prepared by plasma-enhanced chemical vapor deposition of molybdenum pentacarbonyl 1-methylbutylisonitrile. This precursor is an interesting alternative for the commonly used molybdenum hexacarbonyl, because the substance is liquid at room temperature, offers sufficient volatility and stability to air and water. The film growth was monitored in situ by a soft X-ray reflectivity measurement. The films were deposited with different plasma gases (hydrogen and oxygen) under different conditions and analysed by Auger electron spectroscopy, X-ray diffraction and spectral ellipsometry.     

掺硼非晶硅薄膜的微结构和电学性能研究

以硅烷(SiH4)和硼烷(B2H6)为气相反应先驱体，采用等离子体增强化学气相沉积法，(PECVD)制备出能应用于液晶光阀光导层的硼掺杂非晶氢硅薄膜。X射线衍射、原子力显微镜和光、暗电导测试表明，一定程度的硼掺杂提高了非晶氢硅薄膜的电导率、降低了非晶氢硅薄膜的光、暗电导比；硼掺杂促进薄膜晶态率的增加和硅晶粒尺寸的增大，薄膜的结晶状态将逐渐从非晶硅过渡到纳米硅，最后发展为多晶硅。红外吸收谱研究表明了大量的硼原子与硅、氢原子之间能形成某些形式的复合体，仅有少量硼元素对受主掺杂有贡献。     

不同反应气源对制备纳米金刚石膜的影响

为确定两种典型的反应气源对制备纳米金刚石膜的影响,分别以CH4/Ar/H2及CH4/N2混合气体作为反应源,用微波等离子体化学气相沉积(MWPCVD)法制备纳米金刚石薄膜.XRD和Raman分析表明两种气源条件下得到的膜材均为金刚石多晶膜,但用CH4/N2气为反应源沉积的膜材中非金刚石相成分明显更多;AFM和SEM对照分析证实所有膜层的平均晶粒尺寸及表面粗糙度均在几十纳米量级,但CH4/N2气源沉积的膜中容易形成异常长大的晶粒,不利于表面质量的提高.研究结果表明,以CH4/Ar/H2混合气体作为反应气源可制备物相组成纯度更高、表面形态更为优越的纳米金刚石膜.     

硼掺杂对非晶硅薄膜微结构和光电性能的影响

以硅烷 (SiH4 )和硼烷 (B2 H6)为气相反应先驱体 ,采用等离子体增强化学气相沉积法 (PECVD)制备出轻掺硼非晶氢硅薄膜。X射线衍射、原子力显微镜和光、暗电导测试表明 ,一定程度的硼掺杂提高了非晶氢硅薄膜的电导率 ,降低了非晶氢硅薄膜的光、暗电导比 ,并促进了非晶氢硅薄膜中硅微晶粒的生长。红外吸收谱研究预示了大量的硼原子与硅、氢原子之间能形成某些形式的复合体 ,仅有少量硼元素对P型掺杂有贡献。     

Field emission characteristics of high-energy ion-irradiated polycrystalline diamond thin films

Diamond thin films have been synthesized by hot-filament chemical vapor deposition process using a mixture of methane and hydrogen gases. The samples were subjected to very high-energy ion irradiation (100 MeV Au⁷⁺ ions). The field emission characteristics of ion-irradiated samples have been studied. High emission currents and low turn-on and threshold fields were obtained for ion-irradiated samples. The as-deposited and the ion-irradiated samples have been characterized by X-ray Diffraction, Scanning Electron Microscopy and Micro-Raman Spectroscopy techniques and the resulting changes are correlated with field emission results.     

Chemical diagnosis of DLC by ESR spectral analysis

Diamond-like carbon (DLC) films were deposited utilizing plasma enhanced chemical vapor deposition (PECVD) with four precursor gases such as methane, ethylene, acetylene and benzene in gas phase. Electron spin resonance (ESR) spectra showed that dangling-bond sites (DBSs) observed in all films were characterized by an isotropic broad single line. The DLC film with unsaturated precursor gases had the higher film growth rate and the higher DBS accumulative rate. Although the DBS in DLC films were quite stable at room temperature under anaerobic conditions, the DBS decayed rapidly to level off toward a limiting value when exposed to air. The stability and reactivity of the DBS in DLC film were assumed to depend on chemical structure of organic gas used as precursor. The detailed-ESR study on DBS of the DLC films could be one of the powerful tools for diagnosing the micro-structural properties and the quality of films.     

Optical emission spectroscopy study of positive direct current bias enhanced diamond nucleation

High nucleation density and crystalline diamond films were deposited on a mirror-polished Si(100) substrate by horizontal microwave plasma chemical vapor deposition using a two step process consisting of positive direct current (dc) bias enhanced nucleation and growth. Optical emission spectroscopy was employed to investigate in situ the plasma emission characterization during positive biasing process. Emission lines from the Balmer series of atomic hydrogen, molecular hydrogen, CH, C₂, and Ar were observed in the visible and ultraviolet ranges when CH₄, H₂, and Ar were used as the reactant gases. The dependence of plasma emission spectra on the deposition parameters, such as biasing voltage, methane concentration and working pressure was investigated. The relative concentrations of neutral atomic hydrogen were estimated by using the Ar emission at 750.4 nm as an actinometer. A significant variation in the emission intensity of the radicals was measured with a change in the biasing voltage. The correlation between the spectra of some species and the quality of diamond films was studied. The results show that CH and C₂ both were important precursor in the diamond deposition, while C₂ was associated with the presence of amorphous phase in the films during positive dc biasing process.     

Crystallographic and electrical properties of platinum film grown by chemical vapor deposition using (methylcyclopentadienyl)trimethylplatinum

Platinum thin films grown by chemical vapor deposition (CVD) using a liquid precursor of (methylcyclopentadienyl)trimethylplatinum were characterized in terms of crystallographic nature, morphology, contaminants, and their influence on electrical properties. The lattice constant of these CVD films (3.91–3.92 Å) is smaller than that of bulk platinum. A high oxygen contaminant is observed, irrespective of the oxygen ratio during growth. A film grown at low oxygen content consists of randomly oriented micro-grains and contains a large amount of carbon contaminants. When the film is grown under oxidative conditions, it shows a 111-textured cylindrical morphology with increasing thickness. The electric resistivity is higher than the bulk standard, and it increases with decreasing oxygen ratio during the film growth. These results indicate that the carbon contaminant causes the randomly oriented micro-grains and contributes to the high residual resistivity.