感应耦合气体放电的理论模型

本文提出了低气压下无极感应耦合气体放电的一维理论模型。放电为磁场激励,稳定的等离子体由交变电磁场所维持,等离子体密度分布和电子温度由折合半径所确定,密度绝对值由电磁功率所确定。文中还讨论了放电系统等效电路的一些性质。     

大气感应耦合等离子体炬管的设计与仿真实验

为提高大气感应耦合等离子体射流加工装置的工作稳定性,设计一种依靠单一零件定位各层介质管的分体式炬管,并研究炬管内等离子体的传热与流动特性. 利用COMSOL Multiphysics仿真分析发现,等离子体的环形加热和流体淤塞回流现象是导致炬管在使用后出现热损伤和刻蚀损伤的主要原因,选用陶瓷材料作为内管和中层管并调整感应线圈的位置,可有效延长炬管的使用寿命. 使用CCD相机实时监控等离子体射流的形态,发现射频功率(P_w)、工作气流量(Q₂)、冷却气流量(Q₃)与射流的整体长度(L)和半高宽度(W)均呈线性递变关系,P_w、Q₂与Q₃的值过高或过低都会导致等离子体射流的形态波动增大. 实验结果表明:当P_w、Q₂ 与Q₃分别设置为900~1 000 W、650 mL·min^-1、16 L·min^-1时,该分体式炬管可产生稳定性较高的等离子体射流,其L值与W值的波动可分别控制在0.50 mm与0.25 mm内,适用于熔石英等光学表面的加工.     

GaAs backside via-hole etching using ICP system

A high etch rate GaAs via-hole process was studied in an inductively coupled plasma system using Cl2/BCl3 gas system. The effects of process parameters on the GaAs etch rate were investigated. The influences of photoresist SiO2 and Ni masks on the resultant profiles were also studied by scanning electron microscopy. A maximum etch rate of 8.9 μm/min was obtained and the etched profiles were optimized.     

Determination of trace multi-elements in coal fly ash by inductively coupled plasma mass spectrometry

The contents of Cr, Cu, Ni, As, Cd and Pb in coal fly ash were determined by a high resolution inductively coupled plasma mass spectrometry method. The sample digestions were performed in closed microwave vessels with HNO3, HClO4 and HF. The optimum conditions for the determination were obtained. The applicability of the proposed method was validated by the analysis of coal fly ash reference material (NIST SRM 1633a). The results show that most of the spectral interferences can be avoided by measuring in the high resolution mode (maximum mass resolution R=9 000). The detection limit is from 0.05 to 0.21 μg/g, and the precision is fine with relative standard deviation less than 4.3%.     

ICP—AES法测定易拉罐铝合金中的有害元素

研究了电感耦合等离子原子发射光谱(ICPAES)测定食品包装铝合金中常见有害元素的方法,考察了铝基体对测定的影响,按GB356285标准方法进行了浸泡实验.方法的检出限为0.5×10     

Determination of trace elements in high purity gold by high resolution inductively coupled plasma mass spectrometry

Trace elements were determined in high purity gold by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). Sample were decomposed by aqua regia. To overcome some potentially problematic spectral interference, measurements were acquired in both medium and high resolution modes. The matrix effects due to the presence of excessive HCl and Au were evaluated. The optimum conditions for the determination was tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits range from 0.01μg/g to 0.28μg/g depending on the elements. The method is accurate, quick and convenient. It has been applied to the determination of trace elements in high purity gold with satisfactory results. Funded by the Hunan Provincial Natural Science Foundation of China(No. 05JJ40017) and Hunan Provincial Education Department of China (No. 07C029, 08C260)     

Trace amounts of impurities in electrolytic manganese metal by sector field inductively coupled plasma mass spectrometry

An analytical method, using sector field inductively coupled plasma mass spectrometry （SF-ICP-MS） for rapid simultaneous determination of Be, Na, Mg, Si, Ca, Ti, V, Cr, Fe, Co, Ni, Cu, Zn, As, Sn, Sb, Pb and Bi in electrolytic manganese metal, was described. At the beginning, the samples were decomposed by HNO3 and H2504, and then analyzed by SF-ICP-MS. Most of the spectral interferences could be avoided by measuring in different mass resolution modes. The matrix effects due to the excess of sulfuric acid and Mn were evaluated. Correction of matrix effects was conducted by using the internal standard elements. The optimum condition for the determination was investigated and discussed. The detection limit is in the range of 0.001-0.169 gg/L. The current method is applied to the determination of trace impurities in electrolytic manganese metal. And experiments show that good results can be obtained much faster, more accurately and conveniently by current method.     

电感耦合连接器的均衡

电感耦合连接器可以用于板级互连的高速数字信号传输．当信号的传输速率增加或使用较大的电感值时,接收端脉冲将遭受过多的符号间干扰,不能有效地恢复信号．针对这个问题,通过分析接收端脉冲产生符号间干扰的原因,提出采用ALTERA驱动端均衡的方案,并给出均衡比例的计算方法．通过选取合适的均衡比例,增加驱动端信号的高频成分,减少低频成分,来提高接收端脉冲的幅度,降低脉冲的符号间干扰,这时在接收端使用一个简单的低功率触发电路就可以很好地恢复信号．仿真结果显示,采用驱动端均衡方案,能够有效地消除符号间干扰,使电感值的选择和信号传输速率相互独立,因此电感值较大的连接器可以传输高速数字信号．     

感应耦合等离子体选择性刻蚀GaN／A1GaN

采用Cl2/Ar作为刻蚀气体．研究了在感应耦合等离子体干法刻蚀GaN、Al0.27，Ga0.73N材料中工艺参数对刻蚀速率及选择比的影响．GaN与Al0.27Ga0.72N之间的刻蚀选择比随自偏压的增大而减小．随感应耦合等离子体功率的增大变化不大．在Cl2／Ar为3：l的刻蚀气体中加入10％的O2对GaN刻蚀速率影响不大．却使Al0.27Ga0.73N刻蚀速率明显下降．从而提高了GaN与Al0.27Ga0.73N之间的刻蚀选择比．对比了采用不同自偏压刻蚀的Al0.27Ga0.73N材料肖特基的特性．发现反向漏电流随自偏压的增大而增大．     

感应耦合等离子体选择性刻蚀GaN/AlGaN

采用Cl₂/Ar作为刻蚀气体,研究了在感应耦合等离子体干法刻蚀GaN、Al_0.27Ga_0.73N材料中工艺参数对刻蚀速率及选择比的影响．GaN与Al_0.27Ga_0.73N之间的刻蚀选择比随自偏压的增大而减小,随感应耦合等离子体功率的增大变化不大．在Cl₂/Ar为3:1的刻蚀气体中加入10％的O₂对GaN刻蚀速率影响不大,却使Al_0.27Ga_0.73N刻蚀速率明显下降,从而提高了GaN与Al_0.27Ga_0.73N之间的刻蚀选择比．对比了采用不同自偏压刻蚀的Al_0.27Ga_0.73N材料肖特基的特性,发现反向漏电流随自偏压的增大而增大．     

Direct Determination of Trace Impurities in High Purity Zinc Oxide by High Resolution Inductively Coupled Plasma Mass Spectrometry

The determination of trace impurities in high purity zinc oxide by high resolution inductively coupled plasma mass spectrometry （ HR-ICP-MS ） was investigated. To overcome some poteutially problematic spectral iuterference, measurements were acquired in both middle and high resolution modes. The matrix effects due to the presence of excess HCl and zinc were evaluated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits ranged from 0.02μg/ g to 6 μg/ g depending on the elements. The experimental resalts for the determination of Na, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Mo, Cd, Sb and Pb in several high purity zinc oxide powders were presented.     

感应耦合电能传输系统的设计

针对感应耦合电能传输系统(ICETS)的互感模型,提出设计ICETS的三要素法：即通过耦合系数、可分离变压器原副边自感比值和副边能量接收电路的品质因数三要素设计ICETS.该方法在谐振状态下,将ICETS的特性参数表示为三要素的函数,根据可分离变压器的传输效率和器件应力要求进行系统设计.论文分析比较ICETS的4种补偿电路,并以原边串联补偿、副边并联补偿（SP）电路为例,设计输出功率为100 W的ICETS样机.结果表明,用三要素法设计ICETS,可分离变压器效率高,补偿电容电压应力小,样机实验证明所提三要素法的正确性.     

大气脉冲放电等离子体电子温度的研究

设计了一种在大气下脉冲放电产生毫米量级等离子体柱的裴置，采用延时光谱法，用3．5kHz直流脉冲电源在气液界面放电，产生等离子体，对其进行了时间分辨光谱研究．根据大气脉冲放电等离子体的光谱图，测量和计算了等离子体的电子温度，并考察了其随放电峰值电压和时间变化的关系．结果表明：电子温度随电压的升高而增加，随时间延长先增大后减小．     

线形同轴耦合微波等离子体诊断及硅薄膜制备

开发了一种新型线形同轴耦合大面积微波等离子体源,针对该新型等离子体源放电空间等离子密度及分布的不明确性,利用朗缪尔单探针法研究了不同放电参数下该等离子体源等离子体密度及空间分布情况。以微波功率,氢氩总流量(氢氩流量比为3∶1)和距石英管的距离Z为3个因素设计正交实验探究了宏观放电参量对等离子体参数的影响。测试结果表明该型等离子体源的电子密度均在1010cm-3以上。其次,诊断了在距石英管Z为14 cm处,等离子体参数沿空间水平的分布情况,探究薄膜的最佳沉积区域。最后,根据等离子诊断情况进行硅薄膜的沉积,由XRD结果表明薄膜为多晶结构,拉曼光谱显示沉积硅薄膜晶化率均在92%以上,沉积速率在8 nm/min。     

电感耦合等离子体法测定桂郁金中的微量元素

以桂郁金为原料,经浓硝酸-双氧水(30％)处理后用微波消解样品,以电感耦合等离子体发射光谱法(ICP-AES)测定其中的Na、B、Mg、Al、P、Ca、Ti、Zn、Ba、Mn、Fe、K含量,Li、Be、Tl、Mo、Pb、Cd、Sr、V、Cr、Cu、Ni、Co等元素的含量则以电感耦合等离子体质谱法(ICP - MS)测定.方法的准确性用国家一级标准物质GBW - 10015、GBW - 10020对比分析证实.试验结果表明:桂郁金中富含Fe、Mn、Ti等微量元素,其中Fe含量最高为360μg/g,而Be、Cd、Mo、TI、V含量较低,均低于1μg/g.该法快速简便、准确率高、精密度好,完全可以满足样品中元素含量测定要求.     

PZY铁电薄膜材料的ECR等离子体刻蚀研究

以SF6和SF6＋Ar为刻蚀气体。采用电子回旋共振等离子体刻蚀工艺成功地对溶胶．凝胶工艺制备的锆钛酸铅铁电薄膜进行了有效的刻蚀去除．研究了不同气体总漉量、混合比、微波功率等因素对刻蚀速率的影响。指出当气体混合比约为20％时。刻蚀速率达到最大值．锆钛酸铅铁电薄膜表面组份XPS能谱分析曲线表明，在SF6和SF6＋Ar气体中。被刻蚀后样品的Pb含量大大减少。TiO2的刻蚀是限制铬钛酸铅铁电薄膜刻蚀速率的主要因素．     

Numerical simulation of temperature and velocity fields in plasma spray

Based on the turbulence jet model,with respect to Ar-He mixture plasma gas injecting to ambient atmosphere,the temperature filed and velocity field under typical working conditions were investigated.Given the conditions of I=900 A,FAr= 1.98 m3/h,FHe=0.85 m3/h,it is found that both the temperature and the velocity undergo a plateau region near the nozzle exit(0～10 mm)at the very first stage,then decrease abruptly from initial 13 543 K and 778.2 m/s to 4 000 K and 260.0 m/s,and finally decrease slowly again.Meanwhile,the radial temperature and radial velocity change relatively slow.The inner mechanism for such phenomena is due to the complex violent interaction between the high-temperature and high-velocity turbulent plasma jet and the ambient atmosphere.Compared with traditional methods,the initial working conditions can be directly related to the temperature and velocity fields of the plasma jet by deriving basic boundary conditions.     

三维等离子体射流中空气的卷吸和粒子的氧化

为了研究等离子体射流中空气的卷吸和由此引起的金属粒子的氧化，建立了等离子体喷涂的三维计算机模型LAVA-P-3D.喷涂系统采用氩 氢混合气的直流电等离子体，粒子材料是钼.三维模型通过求解等离子射流的N-S方程得出混合气体的温度、速度和氧气浓度等的分布，其中考虑了粒子与等离子射流的相互作用.粒子的模拟采取了轨迹追踪法，研究了粒子的加速、传热、熔化和氧化等物理现象.等离子体射流的模拟结果与实验结果相吻合，并且用数值模拟研究了不同大小粒子的温度、速度、和氧的质量分数.研究结果表明，粒子越大，温度、速度和氧质量分数越小；粒子的氧化量随飞行距离的增长而线性增加.     

外部磁场对电-磁场协同增强HiPIMS放电及V膜沉积与性能的调制

为了获得新型HiPIMS稳定放电及制备优质膜层时的最优外部磁场参数,研究外部磁场变化对电-磁场协同增强高功率脉冲磁控溅射((E-MF)HiPIMS)放电及沉积特性的调制过程.在其他工艺参数保持不变的情况下,研究了外部磁场(线圈电流)对HiPIMS钒(V)靶放电规律以及V膜微观结构和性能的影响.采用数字示波器监测HiPI...