Simulation for solving uniformity problem of large area CCP

Abstract

Large area CCP chamber is necessary to many industrial processes, especially upcoming semiconductor industry which conduct large area substrate. However, uniformity problem is occurred when electrode size of CCP is enlarged, such as standing wave effect and skin effect. Past researchers investigated plasma problems after construct chambers. In this problem, large area CCP chamber and its electrodes are expensive and consume large amount of resource when these are constructed in real. For overcome this obstacle, simulation program (CST microwave studio) is used. First investigation was done at three CCP chambers which have different size. The simulation program revealed that standing wave effect is enlarged at electrode size of CCP and RF frequency are increased. After adjust plasma parameter at different gas pressure environment, second investigation was done. The gas pressure effect for field uniformity was very little. To solve non-uniformity effect on large area CCP, multi feeding and electrode concept were suggested. However, multi feeding concept was not useful from the investigation using simulation. Therefore, to establish multi electrode concept at imaginary chambers, appropriate electrode gap size including diffusion property was studied. Two multi electrode CCP models were constructed from two symmetry of circular single electrode. From these two chamber, the phenomena that electric field at center calculated sub-normally large was studied.