Large-area and uniform plasma production by rotating mode radial line slot antennas with densely arrayed slots

Large-area and uniform plasma production is of crucial importance for achieving large-scaled material processing. In particular, with the progress of memory sizes of micro-processors, the uniformity of plasma parameters over large-area is a serious problem for completing sub-micrometer ultra-large-scale integration (ULSI) circuits. On the other hand, it is desirable to control the plasma profiles directly only by the microwave antenna parameters according to the kinds of the process. A radial line slot antenna (RLSA) with densely arrayed slots has already been proposed for plasma processing system and the basic characteristics was confirmed. In our previous work, however, illuminations of locally excited plasma were observed and improvement of the uniformity is urgently required. In this paper, a novel feeding structure using TE/sub 11/ rotating mode in RLSA for plasma production is proposed. Moreover, novel slot patterns with different slot coupling distribution are fabricated and tested. The plasma measurement is performed at 2.45 GHz microwave with power of 1.0-3.0 kW through a quartz glass window into the discharge chamber filled with argon at a pressure of 30 mTorr. The extremely uniform plasma over large diameter is observed and the possibility of control of the plasma distribution in radial direction by changing different slot coupling is verified.