Surface Modification of Nanometre Silicon Carbide Powder with Polystyrene by Inductively Coupled Plasma

An investigation was made into polystyrene （PS） grafted onto nanometre silicon carbide （SIC） particles. In our experiment, the grafting polymerization reaction was induced by a radio frequency （RF） inductively coupled plasma （ICP） treatment of the nanometre powder. FTIR （Fourier transform infrared spectrum） and XPS （X-ray photoelectron spectroscopy） results reveal that PS is grafted onto the surface of silicon carbide powder. An analysis is presented on the effectiveness of this approach as a function of plasma operating variables including the plasma treating power, treating time, and grafting reaction temperature and time.     

Ion Density Distribution in an Inductively Coupled Plasma Chamber

The ion density distribution in the reaction chamber was diagnosed by a Langmuir probe. The rules of the ion density distribution were obtained under the pressures of 9 Pa, 13 Pa, 27 Pa and 53 Pa in the reaction chamber, different radio-frequency powers and different positions. The result indicates that the ion density decreases as the pressure increases, and increases as the power decreases. The ion density of axial position z =0 achieves 5.8×1010 on the center of coil under the power of 200 w and pressure of 9 Pa in the reaction chamber.     

Two-Dimensional Self-Consistent Kinetic Model for Solenoidal Inductively Coupled Plasma

A two-dimensional self-consistent kinetic model was developed to study the influence of the various factors on the electron energy distribution function. These factors include gas pressure the driving frequency, the radius and length of the inductively coupled plasma equipment, the amplitude of the radio-frequency coil current, and the number of turns of rf coils. The spatial profiles of the rf electric field and power density have also been calculated under the same parameters. Numerical results show that the electron energy distribution functions are significantly modified and the spatial profiles of the rf electric field and rf power density are also demonstrated.     

Numerical Investigation of Flow Fields in Inductively Coupled Plasma Wind Tunnels

Numerical simulations of 10 kW and 110 kW inductively coupled plasma （ICP） wind tunnels were carried out to study physical properties of the flow inside the ICP torch and vacuum chamber with air as tile working gas. Two-dimensional compressible axisymmetric Navier- Stokes （N-S） equations that took into account 11 species and 49 chemical reactions of air, were solved. A heat source model was used to describe the heating phenomenon instead of solving the electromagnetic equations. In the vacuum chamber, a four-temperature model was coupled with N-S equations. Numerical results for tile 10 kW ICP wind tunnel are presented and discussed in detail as a representative case. It was found that the plasma flow in the vacuum chamber tended to be in local thermoehemical equilibrium. To study the influence of operation conditions on the flow field, simulations were carried out for different chamber pressures and/or input powers. The computational results for the above two ICP wind tunnels were compared with corresponding experimental data. The computational and experimental results agree well, therefore the flow fields of ICP wind tunnels can be clearly understood.     

Thermochemical Nonequilibrium 2D Modeling of Nitrogen Inductively Coupled Plasma Flow

Two-dimensional (2D) numerical simulations of thermochemical nonequilibrium in?ductively coupled plasma (ICP) flows inside a 10-kW inductively coupled plasma wind tunnel (ICPWT) were carried out with nitrogen as the working gas. Compressible axisymmetric Navier-Stokes (N-S) equations coupled with magnetic vector potential equations were solved. A four-temperature model including an improved electron-vibration relaxation time was used to model the internal energy exchange between electron and heavy particles. The third-order accuracy elec?tron transport properties (3rd AETP) were applied to the simulations. A hybrid chemical kinetic model was adopted to model the chemical nonequilibrium process. The flow characteristics such as thermal nonequilibrium, inductive discharge, e?ects of Lorentz force were made clear through the present study. It was clarified that the thermal nonequilibrium model played an important role in properly predicting the temperature field. The prediction accuracy can be improved by applying the 3rd AETP to the simulation for this ICPWT.     

Enhanced Work Function of Al-Doped Zinc-Oxide Thin Films by Oxygen Inductively Coupled Plasma Treatment

Al-doped zinc-oxide(AZO) thin films treated by oxygen and chlorine inductively coupled plasma(ICP) were compared. Kelvin probe(KP) and X-ray photoelectron spectroscopy(XPS) were employed to characterize the e?ect of treatment. The results of KP measurement show that the surface work function of AZO thin films can increase up to 5.92 eV after oxygen ICP(O-ICP)'s treatment, which means that the work function was increased by at least 1.1 eV. However, after the treatment of chlorine ICP(Cl-ICP), the work function increased to 5.44 eV, and the increment was 0.6 eV. And 10 days later, the work function increment was still 0.4 eV after O-ICP's treatment, while the work function after Cl-ICP's treatment came back to the original value only after 48 hours. The XPS results suggested that the O-ICP treatment was more e?ective than Cl-ICP for enhancing the work function of AZO films, which is well consistent with KP results.     

A Method to Construct Plasma with Nonlinear Density Enhancement Effect in Multiple Internal Inductively Coupled Plasmas

A method is proposed to built up plasma based on a nonlinear enhancement phenomenon of plasma density with discharge by multiple internal antennas simultaneously. It turns out that the plasma density under multiple sources is higher than the linear summation of the density under each source. This effect is helpful to reduce the fast exponential decay of plasma density in single internal inductively coupled plasma source and generating a larger-area plasma with multiple internal inductively coupled plasma sources. After a careful study on the balance between the enhancement and the decay of plasma density in experiments, a plasma is built up by four sources, which proves the feasibility of this method. According to the method, more sources and more intensive enhancement effect can be employed to further build up a high-density, large-area plasma for different applications.     

Enhanced Work Function of Al-Doped Zinc-Oxide Thin Films by Oxygen Inductively Coupled PlasmaTreatment简

Al-doped zinc-oxide （AZO） thin films treated by oxygen and chlorine inductively coupled plasma （ICP） were compared. Kelvin probe （KP） and X-ray photoelectron spectroscopy （XPS） were employed to characterize the effect of treatment. The results of KP measurement show that the surface work function of AZO thin films can increase up to 5.92 eV after oxygen ICP （O-ICP）＇s treatment, which means that the work function was increased by at least 1.1 eV. However, after the treatment of chlorine ICP （CI-ICP）, the work function increased to 5.44 eV, and the increment was 0.6 eV. And 10 days later, the work function increment was still 0.4 eV after O-ICP＇s treatment, while the work function after Cl-ICP＇s treatment came back to the original value only after 48 hours. The XPS results suggested that the O-ICP treatment was more effective than CI-ICP for enhancing the work function of AZO films, which is well consistent with KP results.     

砂岩铀矿地质样品中铀含量仲裁分析方法——同位素稀释电感耦合等离子体质谱法

本工作研究铀矿地质样品中铀含量仲裁分析方法——同位素稀释电感耦合等离子体质谱法。样品经混酸密闭消解溶矿,采用浓缩铀为稀释剂,使用高分辨电感耦合等离子体质谱测定铀同位素比值,进而计算样品中的铀含量。本方法具有明晰的计量溯源特性,铀的测量范围为1～10000μg/g,对于铀含量约为4μg/g的砂岩样品,相对扩展不确定度小于4.0%（扩展因子K=2.57）,可满足砂岩铀矿地质样品中铀含量仲裁分析要求。     

同位素稀释多接收电感耦合等离子体质谱法测量红酒中的痕量铁

使用同位素稀释技术,采用配有六极杆碰撞室的多接收电感耦合等离子体质谱,对红酒标准物质中铁含量进行了测量,得到高精密度同位素丰度比测量结果。同时采用相对测量方法 ICP-MS和 ICP-OES对红酒样品中的铁含量进行了测量,并与同位素稀释质谱法进行了比较,结果符合一致。方法的不确定度分析包含了实验过程中每个步骤所产生的不确定度和使用的标准物质的不确定度,其中,流程空白对方法检测限和精密度的影响不容忽视。建立的红酒中痕量铁含量的同位素稀释质谱方法为标准物质的定值提供了技术支持。     

Microstructure and Mechanical Properties of CrN Films Deposited by Inductively Coupled Plasma Enhanced Radio Frequency Magnetron Sputtering

CrN films have been synthesized on Si（100） wafer by inductively coupled plasma （ICP）-enhanced radio frequency （RF） magnetron sputtering. The effects of ICP power on microstructure, crystal orientation, nanohardness and stress of the CrN films have been investigated. With the increase of ICP power, the current density at substrate increases and the films exhibit denser structure, while the DC self-bias of target and the deposition rate of films decrease. The films change from crystal structure to amorphous structure with the increase of ICP power. The measured nanohardness and the compressive stress of films reach the topmost at ICP power of 150 W and 200 W, respectively. The mechanical properties of films show strong dependence on the crystalline structure and the density influenced by the ICP power.     

核电厂蒸汽发生器淤泥中主要金属元素的电感耦合等离子体发射光谱分析方法研究

核电厂蒸汽发生器淤泥组成成分及其变化趋势对二回路水化学工况控制起着重要的评价和指导作用。本文开发了湿法消解 电感耦合等离子体发射光谱联用分析方法,并将其应用于核电厂蒸汽发生器淤泥元素成分的定量分析。结果显示,淤泥中的主要元素有铝、钙、铬、铁、镁、锰、镍,各元素的质量分数为0.69%～67.76%。本方法的加标回收率为84.3%～110.7%,相对标准偏差不超过0.60%(n=7),方法的检测限为0.04～3.10 μg/L。     

Self-consistent Kinetic Description of the Low-Pressure Solenoidal Inductively Coupled Argon Discharge

Using an one-dimensional slab model, we have studied the electron energy distribution, the anomalous skin effect, and power absorption in the solenoidal-inductively-coupled argon discharge under low pressures (≤1.33 Pa). The electron energy distribution function and rf electromagnetic field in the plasma are determined self-consistently by the linearized Bolztmann equation incorporating with the Maxwell equations. The numerical results show that, at low pressures, the electron energy distribution function exhibits a non-Maxwellian distribution with a long high-energy tail. The anomalous skin effect is greatly enhanced under low pressures and the negative power absorption is also obtained.     

Microstructure,Hardness and Corrosion Resistance of ZrN Films Prepared by Inductively Coupled Plasma Enhanced RF Magnetron Sputtering

ZrN fihns were deposited on Si（111） and M2 steel by inductively coupled plasma （ICP）-enhanced RF magnetron sputtering. The effect of ICP power on the microstructure, mechanical properties and corrosion resistance of ZrN films was investigated. When the ICP power is below 300 W, the ZrN films show a columnar structure. With the increase of ICP power, the texture coefficient （To） of the （111） plane, the nanohardness and elastic modulus of the films increase and reach the maximum at a power of 300 W. As the ICP Power exceeds 300 W, the films exhibit a ZrN and ZrNx mixed crystal structure without columnar grain while the nanohardness and elastic modulus of the films decrease. All the ZrN coated samples show a higher corrosion resistance than that of the bare M2 steel substrate in 3.5% NaCl electrolyte. The nanohardness and elastic modulus mostly depend on the crystalline structure and Tc of ZrN（111）.     

Experimental Study of the Influence of Process Pressure and Gas Composition on GaAs Etching Characteristics in Cl2/BCl3-Based Inductively Coupled Plasma

A study of Cl2/BCl3-based inductively coupled plasma (ICP) was conducted using thick photoresist mask for anisotropic etching of 50 μm diameter holes in a GaAs wafer at a relatively high average etching rate for etching depths of more than 150 μm. Plasma etch characteristics with ICP process pressure and the percentage of BCl3 were studied in greater detail at a constant ICP coil/bias power. The measured peak-to-peak voltage as a function of pressure was used to estimate the minimum energy of the ions bombarding the substrate. The process pressure was found to have a substantial influence on the energy of heavy ions. Various ion species in plasma showed minimum energy variation from 1.85 to 7.5 eV in the pressure range of 20 to 50 mTorr. The effect of pressure and the percentage of BCl3 on the etching rate and surface smoothness of the bottom surface of the etched hole were studied for a fixed total flow rate. The etching rate was found to decrease with the percentage of BCl3, whereas the addition of BCl3 resulted in anisotropic holes with a smooth veil free bottom surface at a pressure of 30 mTorr and 42% BCl3. In addition, variation of the etching yield with pressure and etching depth were also investigated.     

The Spatial Effects of Antenna Configuration in a Large Area Inductively Coupled Plasma System for Flat Panel Displays

Spatial distributions of plasma parameters such as electron density, electron temperature and electric potential were investigated using a commercial simulation software （COMSOLTM） to predict the effects of antenna configuration in a large area inductively cou- pled plasma （ICP） system for flat panel displays. Nine planar antenna sets were evenly placed above a ceramic window. While the electron density was influenced by both the input current and gas pressure, the electron temperature and electric potential were dominantly affected by the gas pressure.     

The Tuned Substrate Self-bias in a Radio-frequency Inductively Coupled Plasma

The radio frequency (rf) self-bias of the substrate in a rf inductively coupled plasma is controlled by means of varying the impedance of an external LC network inserted between the substrate and the ground. Experimental studies were done on the relations of the tuned substrate self-bias with varying discharge and external circuit parameters. Under a certain discharge gas pressure, the curves of tuned substrate self-bias Vtsb versus tuning capacitance Ct demonstrate jumps and hysteresises when rf discharge power is higher than a threshold. The hysteresis loop in terms of △Ctcrit1(= Ccrit1 -- Ccrit2, here, Ccrit1, Ccrit2 are critical capacitance magnitudes under which the tuned substrate self-bias jumps) decreases with increasing rf discharge power, while the maximum |Vtsbimn| is achieved in the middle discharge-power region. Under a constant discharge power |Vtsb min|, Ctcritl and Ctcrit2 achieve their minimums in the middle gas-pressure region. When the tuning capacitance is pre-set at a lower value, Vtsb varies slightly with gas-flow rate; in the case of tuning capacitance sufficiently approaching Ctcritl, Vtsb undergoes the jump and hysteresis with the changing gas-flow rate. By inserting a resistor R into the external network, the characteristics of Vtsb -- Ct curves are changed with the reduced quality factor Q depending on resistance values. Based on inductive- and capacitive-coupling characteristics of inductively coupled plasma, the dependence of a plasma sheath on plasma parameters, and the impedance properties of the substrate branch, the observed results can be qualitatively interpreted.     

Simulation of Dual-Electrode Capacitively Coupled Plasma Discharges

Dual-electrode capacitively coupled plasma discharges are investigated here to lower the non-uniformity of plasma density. The dual-electrode structure proposed by Jung splits the electrode region and increases the flexibility of fine tuning non-uniformity. Different RF voltages,frequencies, phase-shifts and electrode areas are simulated and the influences are discussed. RF voltage and electrode area have a non-monotonic effect on non-uniformity, while frequency has a monotonic effect. Phase-shift has a cyclical influence on non-uniformity. A special combination of 224 V voltage and 11% area ratio with 10 MHz lowers the non-uniformity of the original set(200 V voltage and 0% area ratio with 10 MHz) by 46.5%. The position of the plasma density peak at the probe line has been tracked and properly tuning the phase-shift can obtain the same trace as tuning frequency or voltage.