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1.
分别通过Langmuir探针测量和动力学模型模拟方法研究了射频感应耦合Ar-N2等离子体中电子能量分布、电子温度、电子密度等物理量随N2含量的变化规律.实验研究结果表明:电子能量分布呈现出非Maxwell型分布,并由双温分布向三温分布过渡;电子温度在不同的气压下随N2含量的增加呈现出不同的变化规律.在放电气压小于1.3 Pa时,电子温度随N2含量的增加而下降;当气压大于1.3 Pa时,电子温度随N2含量的增加先迅速上升而后缓慢下降.在不同的放电气压下,电子密度随N2含量的增加迅速下降.数值模拟结果与Langmuir探针测量结果趋势一致. 相似文献
2.
使用朗谬尔探针方法研究了低压CF4气体感应耦合等离子体(ICP)的放电特性.结果表明 ,CF4等离子体的电子呈现双温分布:一类是密度低、能量高的快电子,另一类是密度高 、能量低的慢电子.快电子温度The、慢电子温度Tce以及它们的平均 电子温度Te随射频输入功率的增加而下降;而它们的密度nhe,nce和ne随功率的增加而上升.从电子与气体粒子碰撞能量平衡的角度解释了双温电子特性与射频输入功率之间的关系.
关键词:
感应耦合等离子体
CF4气体
朗谬尔探针
电子温度 相似文献
3.
通过用Monte Carlo方法模拟N2-H2 混合气体直流辉光放电等离子体快电子行为,从不同H2浓度的电子能量分布函数,电子密度以及ef-N2碰撞率等方面,研究了加H2对氮辉光放电等离子体过程的影响. 研究结果表明: 随着H2浓度的升高,电子的平均能量增加, 电子密度及ef-N2的各种非弹性碰撞率减小; 但在
关键词:
2-H2辉光放电')" href="#">N2-H2辉光放电
Monte Carlo模拟
2碰撞率')" href="#">e-N2碰撞率 相似文献
4.
利用强度标定的发射光谱法,研究了感应耦合CF44/CH44等离 子体中空间基团的 相对密度随宏观条件(射频输入功率、气压和流量比)的变化情况. 研究表明:在所研究的 碳氟/碳氢混合气体放电等离子体中除了具有丰富的CF,CF22,CH,H和F等活 性基团外 ,还同时存在着C22基团,其相对密度随着放电功率的提高而增加;随着气压 的上升呈 现倒“U”型的变化. C22随流量比R(R=[CH4
关键词:
发射光谱
感应耦合等离子体
2基团')" href="#">C22基团 相似文献
5.
利用辉光放电技术采用等离子体质谱诊断的方法研究了不同工作 压强下H2/C4H8混合气体等离子体中 主要正离子成分及其能量的变化规律, 并分析了压强对H2/C4H8混合气体的离解机理以及主要正离子形成过程的影响. 结果表明: 随着工作压强的增加, 碳氢碎片离子的浓度和能量均逐渐减小. 当工作压强为5 Pa时, H2/C4H8混合气体等离子体中C3H5+相对浓度最大; 压强为10 Pa时, C3H3+相对浓度最大; 压强为15, 20 Pa时, C2H5+相对浓度最大; 压强为25 Pa时, C4H9+相对浓度最大. 对H2/C4H8等离子体中的主要组分及其能量分布所进行的定性分析, 将为H2/C4H8混合气体辉光放电聚合物涂层的工艺参数优化提供参考技术基础.
关键词:
辉光放电技术
等离子体质谱诊断
工作压强 相似文献
6.
甚高频(频率大于30 MHz)耦合放电源由于能产生大面积高密度的等离子体而受到了人们的广泛关注. 采用电流、电压探针以及朗缪尔探针诊断技术对60MHz射频激发产生的容性耦合等离子体的放电特性及电子行为进行了研究. 实验结果表明,等离子体的等效电阻/电容随着射频输入功率的增加而减小/增加;等离子体中电子行为不仅依赖于射频输入功率,还与放电气压密切相关;放电气压的增加导致电子能量概率分布函数(EEPF)从双温Maxwellian分布向Druyvesteyn分布转变,而且转变气压远低于文献所报道的数值,这主要是由于在60MHz容性耦合等离子体中电子反弹共振加热效率大为降低.
关键词:
甚高频容性耦合等离子体
朗缪尔探针诊断
电子加热模式 相似文献
7.
Langmuir探针诊断低压氢等离子体电子密度与温度 总被引:1,自引:0,他引:1
为研究实验参数对螺旋波诱导的低压氢等离子体状态的影响,用Langmuir探针对等离子体伏安特性曲线进行了原位诊断,采用双曲正切函数的指数变换模型拟合曲线,根据Druyvesteyn方法得到状态参数电子密度、有效电子温度和电子能量几率函数,分析了它们随实验参数的变化规律。结果表明:射频输入功率、气压和约束磁场对等离子体状态有较大影响。随着射频射入功率增大,放电模式发生转变,电子密度跳跃增长;随着气压增大,电子密度先增大后减小,1.5 Pa为最佳电离气压,随约束磁场的增强呈线性增长;有效电子温度随功率和气压的增大而下降,随约束磁场的增强线性降低,电子能量几率函数曲线峰位和高能部分都向低能移动,与有效电子温度变化规律吻合。 相似文献
8.
9.
使用补偿朗缪尔探针诊断技术,研究了60MHz/13.56MHz双频激发容性耦合等离子体的空间电子行为,得到了电子能量概率函数(EEPF)随径向位置和低频输入功率的演变行为. 实验结果表明,13.56MHz射频输入功率的变化主要影响低能电子的布居,其影响随气压升高而加大. 在等离子体放电中心以外,EEPF呈现出双峰分布的特性,同时发现从放电中心到极板边缘,次能峰有逐渐向高能区漂移的现象,次能峰的出现显示了中能电子的增强的加热效应. 通过EEPF方法,计算了等离子体的电子温度、电子密度. 讨论了等离子体中的电
关键词:
双频激发容性耦合等离子体
朗缪尔探针诊断
电子加热模式 相似文献
10.
采用快电子和重粒子(N2+,N+,Nf)混合的Monte Carlo模型,研究了氮直流辉光放电等离子体金属表面氮化过程中.e-N2s及N2+-N2s两种碰撞离解过程产生的原子态粒子(N+,N)的产生率和氮化粒子(N+,Nf)轰击靶表面的能量、粒子数密度及入射角分布随气体温度的变化规律.结果表明,使阴极靶处活性粒子(N+,Nf)的能量高且粒子数密度大,存在一个最佳放电温度;粒子(N+,N)的产生率及在靶表面的密度数都随着放电气体温度的升高而减少;有大量中性快原子Nf在工件表面小角入射,且粒子(N+,Nf)角分布受温度的影响很小. 相似文献
11.
Low-pressure plasma of gas mixture of Ar, O2 and N2 generated by RF magnetron sputtering was characterized by Langmuir probe and optical emission spectroscopy (OES). The electron temperature (Te), ion density (ni) and electron energy distribution function (EEDF) in Ar-O2-N2 plasma atmosphere were calculated from I-V characteristic of Langmuir probe. Boltzmann plot method was applied for calculating the vibrational temperature (Tvib) of the second positive system of N2 (N2SPS) in Ar-O2-N2 plasma. The Te, ni, EEDF and Tvib in Ar-O2-N2 plasma were studied as a function of O2 percentages. It was found, the Tvib increased from 0.47 eV to 0.55 eV as the oxygen percentage in Ar-N2-O2 plasma increased from 10% to 40%. Further, the Te increased from 1.6 eV to 3 eV as the O2 concentration increased from 10% to 40%. 相似文献
12.
采用射频反应溅射法在玻璃衬底上制备Zn3N2薄膜,然后向真空室中通入纯氧气进行热氧化制备ZnO薄膜.利用X射线衍射、扫描电子显微镜、霍尔效应测量、透射光谱和光致发光光谱等表征技术,研究了氧化温度和氧化时间对ZnO薄膜的结晶质量、电学性质和光学性能的影响.研究结果显示,450 ℃ 下氧化2 h后的样品中除含有ZnO外,还有Zn3N2成分,500 ℃下氧化2 h可以制备出电阻率为0.7 Ωcm,空穴载流子浓度为10关键词:
p型ZnO薄膜
3N2薄膜')" href="#">Zn3N2薄膜
射频溅射
原位氧化 相似文献
13.
A parametric study of the electron energy distribution function (EEDF) and the electron mobility in the mixture Na + Ar +
N2 is carried out. An analysis is made of the conditions that obtain in a photoplasma when the detachment of the mean electron
energy from the neutral gas temperature is due to superelastic collisions (collisions of the second kind) with excited sodium
atoms. The case of low ionization of the medium at low vibrational temperatures of the ground state of the nitrogen molecules
is considered. To find the EEDF a numerical solution of the Boltzmann transport equation is carried out. It is found that
in the indicated mixture the presence of nitrogen leads to a depletion of the EEDF in the region of efficient vibrational
excitation of the molecules and promotes the formation of inversion in the EEDF ∂f(ɛ)/∂ɛ>0 in the energy range corresponding to the Ramsauer minimum in the cross section of elastic collisions of electrons with
the argon atoms. It is shown that the nonequilibrium character of the EEDF leads to a complicated dependence of the electron
mobility on the partial ratios of the components of the mixture, the degree of ionization of the medium, and the population
of the resonantly excited sodium atoms.
Zh. Tekh. Fiz. 69, 14–19 (April 1999) 相似文献
14.
R. Plasil I. Korolov T. Kotrik P. Dohnal G. Bano Z. Donko J. Glosik 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,54(2):391-398
Experimental studies of the electron energy distribution function “EEDF” under well defined conditions in flowing afterglow
plasma, using a Langmuir probe are reported. The EEDF is measured in He2
+ and Ar+ dominated plasmas and in XeH+ and XeD+ dominated recombining plasmas. He is used as a buffer gas at medium pressures in all experiments (1600 Pa, 250 K). The deviation
of the measured EEDF from Maxwellian distribution is shown to depend on plasma composition and on the processes governing
the plasma decay. The influence of energetic electrons produced during the plasma decay on the body and tail of the EEDF is
observed. The mechanism of energy balance in afterglow plasma is discussed. 相似文献
15.
16.
Yu. Z. Ionikh N. B. Kolokolov A. V. Meshchanov N. V. Chernyshova 《Optics and Spectroscopy》2000,88(4):502-505
The electron energy distribution function in the afterglow of a low-pressure discharge in an Ar-N2 mixture was experimentally found. The values of electron temperature were determined. At the initial stage of plasma decay, the electron temperature was shown to be close to the nitrogen vibrational temperature. A study was made of the afterglow observed in the bands of the first negative system of N + 2 , and it is shown that this afterglow may be attributed to collisions of argon ions with nitrogen molecules found on higher vibrational levels. 相似文献
17.
ABSTRACTThis study focuses on the glow discharge generated with a gases mixture of Ethanol (C2H5OH) and Helium (He), at different concentrations maintained at a total pressure of 2.0 Torr. We used optical emission spectroscopy (OES) to analyze the discharge mixture at different concentrations of Helium. Single Langmuir probe data was used to determine the Electron Energy Distribution Function (EEDF). For the total C2H5OH/He mixture plasma concentrations, the EEDF has a Maxwellian distribution function. A decrease in He concentration results in significant changes in the EEDF, this behavior is related to the increase in the C2H5OH percentage must increase the energy loses of the electrons in the inelastic collision with C2H5OH producing a significant change in the EEDF, therefore, the EEDF pattern results in an increase of electron–molecule reaction rates. The rise in electron temperature for increasing Helium percentage is explained by the decreasing electron energy loss in the inelastic collisions with C2H5OH molecule. It observes a decrease of electron density ne as a function of the Helium percentage, which can be related to the ratio between ionization cross sections of Helium and C2H6O molecule. The active species are generated in the electron-molecule processes, which are associated with electron impact dissociation of C2H5OH and Helium electronic impact excitation in the gas phase. The emission optical spectra (OES) show changes in the intensity of the most important peaks of the plasma mixture, which indicates the dependence in the formation of the plasma as a function of the percentage of the gases. The changes in the intensities of the same observed species are due to different processes of excitation and ionization energies of the system, in addition to the increase of He metastable states He I. Hydrogen is the main product obtained from the decomposition of C2H5OH. 相似文献
18.
The present paper is a review of recent works related to the optical emission spectroscopy applied to the determination of
ground state densities of N atoms in Ar-N2 flowing post-discharges. The effect of small quantities of H2 in the Ar-N2 discharge on N atom densities within the post-discharge has been analysed. The authors demonstrate that optical emission
of Na impurity may be applied to the determination of the vibrational temperature of N2(X,v) states at the temperatures usual for nitriding of metals in Ar-N2 post-discharge. From the diagnostic of Ar-N2 post-discharges, it is clearly specified that nitriding of iron base alloys in a flowing post-discharge reactor is originating
in N atoms, especially when a few H2 molecules are admixed into the Ar-N2 discharge. Finally, correlation between the N-atom density and the thickness of the iron nitrided layers when H2 is introduced into the Ar-N2 discharge are given.
Dedicated to Prof. Jan Janča on the occasion of his 60th birthday. 相似文献
19.
In this study (α/p) = f(E/p) functional relation is derived for the gas mixture of N2/O2 by considering Townsend approach, and formation mechanism of corona discharge is investigated for the coaxial electrode system located in this gas medium. The electron energy distribution function (EEDF) which is required for estimation of ionization coefficient, is determined by considering probability distribution function of inelastic electron collisions versus energy. An algorithm for determining ionization coefficient for binary gas mixture is presented. The development and motion of the electron avalanche in inter-electrode gap are studied by considering the effect of positive space charges. It is determined by considering the derived mathematical expressions that the formation of corona discharge is related with the variation of the current characteristics in inter-electrode gaps depending on the change of potential of central electrode. 相似文献
20.
Floating double probe in non‐Maxwellian plasmas: Determination of the electron density and mean electron energy 下载免费PDF全文
A theoretical study of the floating double probe based on the Druyvesteyn theory is developed in the case of non‐Maxwellian electron energy distribution functions (EEDFs). It is used to calculate the EEDF in the electron energy range larger than –e(Vf ? Vp) from the I–V double probe characteristics. Vf and Vp are the floating and plasma potential, respectively. The analytical distribution function corresponding to the best fit of EEDF in the energy range larger than e(Vf ? Vp) allows the determination of the total electron density (ne) and the mean electron energy (<?e>). The method is detailed and tested in the case of a theoretical Maxwell–Boltzmann distribution function. It is applied for experiments that are performed in expanding microwave plasmas sustained in argon. Analytical EEDFs determined by this method are compared with those measured by means of single probes under the same experimental conditions. A good agreement is observed between single and double probe measurements. Results obtained under different experimental conditions are used to define the best conditions to obtain reliable results by means of the double probe technique. 相似文献