Large-diameter plasma sourcs for plasma processing

大直径、高密度等离子体的生产是建立广域等离子体加工的关键。本联合研究的目的是开发新的等离子体源，以产生大直径均匀等离子体。该研究将东北大学开发的射频和ECR放电等离子体控制技术与韩国科学技术院（KAIST）和KBSI开发的利用光学探针系统检测f自由基的诊断技术相结合。澄清等离子体密度和自由基密度分布之间的关系也很重要。为了在东北大学进行实验，我们制作了一个直径60厘米的MMT（改良磁控管型）射频器件，在那里研究了产生大直径等离子体的条件。研究发现，射频电极的长度和射频电极上的磁场强度对均匀等离子体的产生至关重要。当放置在机器末端的亚电极的射频阻抗设置为与射频频率平行共振时，更有可能产生高密度等离子体。我们可以在500 W的射频功率下产生10^<11>/cm^3的等离子体。在直径130 cm的大腔室中，利用MMT射频放电进行了类似的实验。我们证实了直径超过120厘米的等离子体的均匀性为5%。在东北大学与韩国研究人员合作，在ECR和MMF RF放电等离子体中测量了CF_4等离子体中F自由基的分布。光学探针系统是在东北大学为测量而建立的。我们发现F型径向轮廓对气体压力有很强的依赖性。为了确定聚硅的实际蚀刻轮廓与自由基轮廓之间的关系，在不同的条件下进行了蚀刻，我们发现蚀刻轮廓与自由基密度相似。少

The productions of large-diameter, high density plasma are of crucial importance to establish a wide-area plasma processing. The object of this joint reseach is to develop new plasma sources for producing a large-diameter uniform plasma. The reseach has been proceeded by combining the plasma control techniques developed at Tohoku University for RF and ECR discharges with the diagnostic techniques developed at KAIST and KBSI,Korea, for detecting F-radicals by using a optical probe system. It is also quite important to clarify the relation between the distributions of plasma density and radical density.In order to carry out the experiment at Tohoku University, we produced a 60-cm-diameter MMT (Modifoed Magnetron Type) RF devices, where the conditions for producing a large-diameter plasma are inverstigated. It was found that the length of the RF electrode and the strenth of the magnetic field on the RF electrode are quite essential for the uniform plasma production. Is was also found that … More the production of high density plasma is possible when the RF impedance of a sub-electrode placed at the end of the machine was set at a parallel resonance with the RF frequency. We can produce a plasma of 10^<11>/cm^3 at the RF power of 500 W.Similar experiment was also carried out in a large chamber of 130 cm in diameter by using MMT RF discharge. We confirmed that a quite uniform plasma is prroduced over 120 cm in diameter with a uniformity of 5%.The profiles of F radicals in CF_4 plasmas were also measured in ECR and MMF RF discharge plasmas at Tohoku University in collaboration with the Korean staffs. The optical probe system was build up at the Tohoky University for the measurements. We found that the F radial profiles have a strong dependency on the gas pressuer. In order to confirm the relation between the actual etching profile of poli-silicon and the radical profile, the etching has been preformed under different conditions, and we found that a similar profile of etching with the radical density. Less