Research on Large-Scaled Line Plasma Production by Microwave

在太阳能电池薄膜CVD、平板显示器（FPD）、大面积薄膜的各种表面改性等制造业的材料加工中，长线状等离子体是不可避免的。在这项工作中，一个新提出的大规模线等离子体生产的方法进行了研究。在这种方法中，频率为2.45 GHz的微波功率在一个狭窄的和扁平的矩形波导被用来产生一个长的均匀的线性等离子体。由于波导的宽度非常接近截止条件，波导内的微波波长被极大地延长，制备了长1.0和2.0 m，高5 mm的窄矩形波导，波导宽度为61.5 mm-62.0 mm，与切割线非常接近。微波炉的关闭状态。波导管的上表面有一个长的线性缝隙天线，用于将微波功率发射到放电等离子体中 ...更多信息 1.0和2.0米长的腔室。在波导的端部安装一个短柱塞，以产生驻波并调节驻波的相位，从而提高等离子体的均匀性。在100 mTorr至500 mTorr的压力下的Ar等离子体是通过采用极长的微波波长产生的。用朗缪尔探针对等离子体参数进行了三维测量，结果表明，电子密度的轴向分布非常平坦，整个等离子体长度超过2 m，等离子体均匀性在4%以内。在短柱塞位置，电子密度分布呈驻波状。具体而言，在固定轴向位置测量的电子密度显示出驻波状轮廓，表明短柱塞具有预期的驻波产生和移相器功能。等离子体中的电子密度值显示出非常高的值，<12><-3>在100 mTorr的压力和1 kW的微波功率下高达1 × 10 ~（-6）cm ~（-1），表明等离子体中的电子密度足够高，高于微波的截止条件。实验证实，轴向均匀等离子体产生在微波中具有阈值，超过该阈值，电子密度变得充分高于微波截止密度。在这种条件下，微波功率到达短柱塞上并被反射，产生驻波，从而大大改善了等离子体的均匀性。结果表明，该方法可以提供一种有效的大规模线性均匀等离子体产生的工具，长度超过2米。少

Long line-shaped plasmas are inevitable in material processing in manufacturing industries, such as solar cell film CVD, flat panel displays (FPDs), and various surface modification of large-area thin films. In this work, a newly proposed method of large-scaled line plasma production is studied. In this method, microwave power of frequency of 2.45 GHz in a narrowed and flattened rectangular waveguide is employed to produce a long uniform linear plasma. Since the width of waveguide is very close to the cutoff condition, the wavelength of microwave inside the guide is extremely lengthened, providing a condition of long linear high density plasma with a great uniformity.The narrowed rectangular wave-guide of 1.0 and 2.0 m in length and 5mm in height were prepared and the width of the waveguide is 61.5 mm-62.0 mm which is very closed to the cut-off condition of microwave. The waveguide has a long linear slot antenna on the top surface to launch the microwave power into the discharge plasma … More chamber of 1.0 and 2.0 m in length. At the end of wave guide, a short plunger was quipped to produce a standing microwave and to adjust the phase of the standing wave, hence the uniformity of the plasma thus produced. The plasmas of Ar at the pressures of 100 mTorr to 500 mTorr were produced by employing an extremely long microwave wavelength. The parameters of plasma thus produced were three-dimensionally measured by a Langmuir probe.The axial profile of electron density was extremely flat and the plasma uniformity was within 4 % in the entire plasma over 2 m long. It was also found that the profile of electron density showed a standing wave like profile for the short plunger position. To be specific, the electron density measured in a fixed axial position showed a standing wave-like profile, indicating the short plunger has functions of standing wave generation and the phase-shifter as expected. The value of electron density in the plasma showed a very high value, as high as 1x10^<12> cm^<-3> at the pressure of 100mTorr and the microwave power of 1 kW, indicating that the plasma electron density is adequately high above the cut-off condition of microwave. It was experimentally verified that the axially uniform plasma production has a threshold in microwave, above which the electron density becomes adequately higher than the microwave cut-off density. In these conditions, the microwave power comes onto the short plunger and is reflected, producing a standing wave, and thus the plasma uniformity can be improved very much. It is concluded thus that the present method can provide a powerful tool of large-scaled linear uniform plasma production in length more than 2 m. Less