微波ECR等离子体辅助磁控溅射沉积装置的研制

本文介绍了一种新型的沉积装置──微波ＥＣＲ等离子体辅助磁控溅射沉积装置。通过对装置性能的测试及沉积试验表明，该装置具有与离子束辅助沉积相类似的效果，但与离子束辅助沉积装置相比，该装置提高了成膜的沉积速度，降低了设备成本，为薄膜沉积提出了一条新途径．     

圆柱谐振腔式微波等离子体金刚石膜CVD沉积室的FDTD模拟与优化

微波等离子体化学气相沉积(MPCVD)技术被认为是制备高质量金刚石膜的一种最重要的技术手段。对微波等离子体金刚石膜沉积装置进行模拟与优化,可大大减少设计和改进MPCVD装置时所需要的时间与成本。本文在结合使用谐振腔质量因子和沉积台上方等离子体的密度与分布两个优化判据的基础上,采用Matlab语言和时域有限差分方法,模拟了圆柱谐振腔式微波等离子体金刚石膜沉积装置,并对其主要尺寸进行了优化。     

基片位置对微波等离子体合成金刚石的影响

用自制的微波功率为5kW的微波等离子体(MPCVD)装置、用H2/CH4/H2O作为反应气体在较高的沉积气压(12.0kPa)条件下,研究了基片放置在等离子体球边缘附近不同位置对CVD金刚石沉积和生长的影响。结果表明,CVD金刚石的形核和生长对环境的要求是不同的;在等离子体球边缘处不利于金刚石的形核,但有利于高质量金刚石的沉积。     

微波等离子体化学气相沉积金刚石膜装置的研究进展

综述了各种微波等离子体化学气相沉积（MPCVD）金刚石膜装置的结构及工作原理,并对它们各自的优缺点做了比较分析;基于MPCVD金刚石膜装置的发展现状,构想设计了一种新型高效的大功率大面积快速沉积CVD金刚石膜装置,并对其可行性做了初步分析研究。     

水冷反应室式MWPCVD制备金刚石膜装置研制

微波等离子体化学气相沉积(MWPCVD)是制备金刚石膜的一种重要方法.为了获得金刚石膜的高速率大面积沉积,研制成功了水冷反应室式MWPCVD制备金刚石膜的装置.装置在微波输入功率为3.0 kW时能长时间稳定运行,并在硅衬底上沉积出金刚石膜.     

碳纳米管异质结构的 ECR-CVD法制备

使用电子回旋共振微波等离子体化学气相沉积方法（ECR-CVD），以Fe3O4纳米粒子为催化剂，多孔硅为基底，采用CH4／H2和CH4／B2H6／H2两种气源在连续的CVD过程中大量合成了一种新型的纳米管异质结构．扫描电镜（SEM）和透射电镜（TEM）观察表明：合成的异质结构一端是类竹节状的掺硼碳纳米管，另一端是光滑中空的纯碳纳米管．异质结构采用底端生长模式，先行生长的掺硼纳米管处于纳米管结构的顶端．     

新型MPCVD装置在高功率密度下高速沉积金刚石膜

使用自行研制的新型MPCVD装置,以H2-CH4为气源,在输入功率为5kW,沉积压力分别为13.33、26.66kPa和不同的甲烷浓度下制备了金刚石膜。利用等离子体发射光谱法对等离子体中的H原子和含碳的活性基团浓度进行了分析。用扫描电镜、激光拉曼谱对金刚石膜的表面和断口形貌、金刚石膜的品质等进行了表征。实验结果表明,使用新型MPCVD装置能够在较高的功率密度下进行金刚石膜的沉积;提高功率密度能使等离子体中H原子和含碳活性基团的浓度明显增加,这将提高金刚石膜的沉积速度,并保证金刚石膜具有较高的质量。     

厚度对DLC薄膜内应力的影响研究

采用ECR微波等离子体增强化学气相沉积的方法于C1H2/H2/Ar2等离子环境中在单晶Si(111)晶面上制备了不同厚度的DLC膜样品,研究了薄膜的厚度随沉积时间的变化及薄膜的硬度、内应力随厚度的变化关系.结果表明,在沉积时间变化范围内,厚度与沉积时间基本呈线性关系,沉积速率可达80nm/min;制备态样品存在的内应力...     

氧气对MWPCVD制备金刚石膜的影响

在水冷反应室式微波等离子体化学气相沉积装置中以混合的CH4/H2/O2为反应气体,研究了O2浓度对制备金刚石膜的影响.实验发现,很低浓度的O2会显著促进金刚石的沉积,并稍稍抑制非晶C的沉积,因而沉积膜中非晶C的含量急剧下降;较高浓度的O2会同时抑制金刚石和非晶C的沉积,但由于抑制金刚石的作用更强烈,沉积膜中非晶C的含量反而有所升高.另外,O2的存在,有利于沉积颗粒较小的金刚石膜.     

线形微波等离子体CVD金刚石薄膜沉积技术

本文将讨论一种新型的微波等离子体CVD设备———线形微波等离子体CVD设备和其在金刚石薄膜制备技术中的应用。利用Langmuir探针方法对线形微波等离子体CVD设备产生的H2等离子体进行的等离子体参数测量表明,在工频半波激励的条件下,H2等离子体的电子温度和等离子体密度分别约为6 eV和1×1010/cm3。尝试利用线形微波等离子体CVD设备,在直径为0.5 mm的小尺寸硬质合金微型钻头上进行了金刚石涂层的沉积,获得了质量良好的金刚石涂层。由于线形微波等离子体CVD设备产生的等离子体面积具有容易扩大的优点,因而在需要使用较大面积等离子体的场合,它将有着很好的应用前景。     

Improvement on the conventional MWECR-CVD system and preparation of hydrogenated amorphous silicon films

In order to obtain a compact-structure, saving-energy and good-property system based on the conventional microwave electron-cyclotron resonance chemical vapor deposition (MWECR-CVD) system, we proposed a new technique using a magnetic field combination of an electromagnetic coil and a permanent magnet unit, as well as adopting a dedicated microwave coupling structure. The experiment results showed that by using this new optimized system the deposition rate can reach more than 2.5 nm/s, and the photosensitivity of a-Si:H films can be up to 1.1×10⁵.     

高致密度FeNi纳米颗粒薄膜制备与性能研究

传统磁控溅射装置制备的纳米颗粒薄膜粒径不均一并且实现粒径大小调控比较困难.本研究采用电场辅助沉积技术,在沉积平台施加5～30 kV的电场,以Si(100)为衬底制备了一系列纳米颗粒粒径均一的高致密度FeNi纳米颗粒薄膜材料.通过XRD、SEM以及VSM测量,研究了不同沉积电场下FeNi纳米颗粒薄膜的结构、形貌和磁性能....     

A dynamic bistability in two-layer magnetically-coupled films

The dynamic behavior of magnetic moments in a two-layer magnetically coupled film system was studied in the region of ferromagnetic resonance with large amplitudes of the precession angle. The system exhibits manifestations characteristic of the nonlinear phenomena, including (i) a shift in the resonance frequency with increasing microwave field strength and (ii) the existence of dynamic bistability regions with respect to the microwave frequency and the magnetizing field strength.     

The control of the high-density microwave plasma for large-area electronics

A uniform, low-temperature, and high-density microwave plasma (2.45 GHz) is produced without magnetic field, utilizing a spokewise antenna. The plasma maintains a uniform state in Ar low pressure of several 10 mTorr with high electron density, >10¹¹ cm⁻³, and a temperature less than 2.5 eV within ±6% over 16 cm in diameter. Highly crystallized and photoconductive, hydrogenated microcrystalline silicon (μc-Si:H) film is produced from dichlorosilane (SiH₂Cl₂), H₂ and Ar mixture at high deposition rate of more than 5 Å/s. This low-temperature and high-density microwave plasma source has a high potential not only for etching but for future large-area film deposition processes.     

Dependence of the a-Si:H defect density of states on the magnetic field profile of an electron cyclotron resonance microwave plasma

The magnetic field profile of an electron cyclotron resonance microwave plasma was systematically altered to determine subsequent effects on a-Si:H film quality. The mobility gap deep density N_D deposition rate and light-to-dark conductivity were determined for the a-Si:H films. By variation of the magnetic field profile N_D could be altered by more than an order of magnitude, from 1 × 10¹⁶ to 1 × 10¹⁷ cm⁻³ at 0.7 mTorr and 1 × 10¹⁶ to 5 × 10¹⁷ cm⁻³ at 5 mTorr as determined by junction capacitance techniques. Two deposition regimes were found to occur for the conditions of this study. Highly divergent magnetic fields resulted in poor quality a-Si:H, while for magnetic field profiles defining a more highly confined plasma, the a-Si:H was of device quality and relatively independent of the magnetic field configuration. The data is interpreted as a consequence of silane depletion for highly divergent magnetic field profiles.     

Low-temperature spin spray deposited ferrite/piezoelectric thin film magnetoelectric heterostructures with strong magnetoelectric coupling

We report low-temperature spin spray deposited Fe₃O₄/ZnO thin film microwave magnetic/piezoelectric magnetoelectric heterostructures. A voltage induced effective ferromagnetic resonance field of 14 Oe was realized in Fe₃O₄/ZnO magnetoelectric (ME) heterostructures. Compared with most thin film magnetoelectric heterostructures prepared by high temperature (>600 °C) deposition methods, for example, pulsed laser deposition, molecular beam epitaxy, or sputtering, Fe₃O₄/ZnO ME heterostructures have much lower deposition temperature (<100 °C) at a much lower cost and less energy dissipation, which can be readily integrated in different integrated circuits.     

Crystalline orientation of alumina ceramics prepared by electrophoretic deposition under a high magnetic field

Electrophoretic deposition (EPD) of alumina in a superconducting magnet was performed at various magnetic field strengths. A stable colloidal suspension of alumina appropriate for magnetic alignment was prepared in an ethanol medium by using a phosphate ester (PE) as a dispersant. The amount of PE appropriate for the stability of the alumina suspension was investigated by measuring the pH, zeta-potential and the relative density of the green compacts. The consolidation of alumina powder was performed by EPD under a magnetic field of 0–12 T. The degree of crystalline orientation of the sintered bodies was evaluated by X-ray diffraction (XRD) as a function of the applied magnetic field during deposition and the sintering temperature.     

磁场辅助等离子体增强化学气相沉积

本文根据螺线管线圈内部磁场的分布规律，以及磁场对等离子体内部电子的作用原理，设计了磁场辅助的等离子体增强化学气相沉积（PECVD）系统，并且研究了在PECVD系统中获得均匀磁场的方法。而后，以SiH4和N2为反应气体，在低气压下沉积了SiN薄膜。测量了SiN薄膜的沉积速率，折射率，表面形貌等参数。验证了磁场分布的均匀性，分析了磁场在等离子体增强化学气相沉积系统中的作用。     

Output microwave radiation power of low-voltage vircator with external inhomogeneous magnetic field

Dependence of the power of a broadband microwave radiation generated by a low-voltage oscillator with virtual cathode (vircator) on the parameters of an external inhomogeneous magnetic field has been studied by numerical simulations using a two-dimensional model. It is established that there are optimum parameters of the generator (configuration of the external magnetic field, electron beam current) for which the output radiation power is maximum. A relationship between the optimum conditions of virtual cathode formation in the electron beam and the microwave generation regime is established.     

Deposition of dielectrics using a matrix distributed electron cyclotron resonance plasma enhanced chemical vapor deposition system

We have studied the deposition of silicon oxide, oxynitrides and silicon nitride in a novel, scalable, low-pressure high-density plasma system based on the ECR effect and the matrix arrangement of microwave antennas. Silane, nitrogen and oxygen gases were used as precursors. Films were deposited onto different heated and unheated substrates, including silicon, glass and polymer. The influence of the magnetic field configuration, gas flows, reactor pressure, microwave power and radio frequency bias on the uniformity and properties of the films was studied. Ex-situ and in-situ UV-visible spectroscopic phase-modulated ellipsometry and FTIR spectroscopy were used to study the properties of materials and the uniformity of the depositions, along with electrical measurements to evaluate the dielectric properties of the films. Optimizing the magnetic field configuration and applying an RF bias, we were able to achieve an uniformity better than 3.3% across the 200 mm wafers. Stoichiometric silicon oxide films with index values matching that of thermal silica were grown on unheated substrates with rates exceeding 2 nm/s.