Large-diameter plasma sourcs for plasma processing

大直径、高密度等离子体的产生对于建立大面积等离子体加工技术具有重要意义。本研究的目的是开发新的等离子体源，以产生大直径的均匀等离子体。研究工作是将东北大学为RF和ECR放电开发的等离子体控制技术与韩国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进行的。为了在东北大学进行该实验，我们制作了直径60 cm的MMT（Modifoed Magnetron Type）RF装置，对产生大直径等离子体的条件进行了研究。结果表明，射频电极的长度和射频电极上的磁场强度对等离子体的均匀产生至关重要。还发现， ...更多信息 当设置在机器端部的子电极的RF阻抗被设置为与RF频率并联谐振时，可以产生高密度等离子体。我们可以<11>在500 W的射频功率下产生10^ /cm ^3的等离子体。类似的实验也在直径为130 cm的大腔室中通过使用MMT射频放电进行。我们证实，在120 cm以上的直径范围内，产生了均匀度为5%的均匀等离子体。我们还与韩国的研究人员合作，在东北大学的ECR和MMF射频放电等离子体中测量了CF_4等离子体中F自由基的分布。在东北大学建立了用于测量的光学探针系统。我们发现F径向分布对气体压强有很强的依赖性。为了证实多晶硅的实际刻蚀轮廓与自由基浓度之间的关系，在不同条件下进行了刻蚀实验，发现了与自由基浓度相似的刻蚀轮廓。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