Clarification of Microwave Absorption Mechanism in Surface Wave Plasma and Optimization of Plasma-Antenna Coupling

为了开发用于半导体加工的大面积表面波等离子体源，我们开展了表面波等离子体中微波吸收机理的澄清和等离子体-天线耦合的优化等相关研究。主要结果如下：1。大面积表面波等离子体的模式识别：首次提出了2.45 GHz微波激发的大面积平面表面波等离子体的色散关系，并阐明了其中所观察到的跳模现象的机理。微波能量的产生机理：利用潜望镜技术对高能电子进行了光发射测量，研究了微波在感应耦合等离子体射频天线独立产生的等离子体中的传播特性。实验结果表明，在石英窗附近产生了更多的高能电子，并且在截止层中电场得到了强烈的增强，表明在截止层中可能存在能量吸收过程，等离子体电子可能被共振增强的微波场加热。等离子体天线耦合优化：为了研究槽结构和位置对等离子体产生效率的影响，我们测试了不同形状的槽天线。实验结果表明，等离子体的产生效率与槽的结构有关，其中横向槽天线（槽垂直于波导轴线切割）的产生效率优于其他的。波形频率对等离子体产生的影响：为了研究波形频率对表面波等离子体产生的影响，我们比较了在同一等离子体腔中，由2.45GHz和915MHz波形产生的SWPs的等离子体特性。在915MHz波激励下，得到了等离子体密度与入射功率之间的线性产生特性。研究成果：1997-1998年，在国际会议上发表论文13篇（特邀2篇），在国内学术会议上发表论文24篇。少

We have been carried out the research associated with the clarification of microwave absorption mechanism and the optimization of plasma-antenna coupling in the surface wave plasma, aiming for the development of large-area surface wave plasma source for semiconductor processing. Main results are listed in the following.1. Mode identification of large-area surface wave plasma : We have for the first time presented the theoretical dispersion relations of the large-area, planar surface wave plasma excited by 2.45 GHz microwaves and have also clarified the mechanism of mode-jump phenomena observed in it.2. Mechanism of the microwave energy : We have carried out the measurements of optical emission using the periscope technique to study high-energy electrons and have investigated the characteristics of microwave propagation in the plasma which was indipendently produced using the RF antenna for inductively-coupled plasma. From the experimental facts that the high-energy electrons were produ … More ced in the vicinity of the quartz window and the electric field was strongly enhanced in the cutoff layer, we have shown the possibility of the energy absorption process in the cutoff layer, where the plasma electrons might be heated by the resonantly enhanced microwave fields.3. Optimization of plasma-antenna coupling : To investigate the effect of the slot structure and position on the plasma production efficiency, we have tested a various shape of slot antennas. Experimental results showed that the plasma production efficiency depended upon the slot structure and the case of transverse slot antennas(slots were cut perpendicularly to the waveguide axis) was superior to others.4. Effect of wave frequency on the plasma production : To study the effect of wave frequency on the surface wave plasma production, we compared the plasma characteristics of SWPs produced by 2.45GHz and 915MHz waves in the same plasma chamber. It is noted that the linear production characteristics between plasma density and incident power was obtained in the case of 915MHz wave excitation.5. Reasearch results : We have published the present results in 14 journal papers and have reported 13 papers in the international conferences (2 invited) and 24 papers in the domestic symposium and meetings in 1997-1998. Less