Performance of a permanent-magnet helicon source at 27 and 13 MHz
Performance of a permanent-magnet helicon source at 27 and 13 MHz
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DOI：
10.1063/1.4754580
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发表时间：
2012-09-01
影响因子：
2.2
通讯作者：
Chen, Francis F.
中科院分区：
文献类型：
--
作者：
Chen, Francis F.
一个小的螺旋源用来产生致密等离子体，并将其注入一个大的腔室。直流磁场（b场）使用永磁体，使系统非常简单紧凑。虽然理论预测27.12 MHz的天线耦合会更好，但由于理论中没有包括的实际影响，发现13.56 MHz出人意料地提供了更高的密度。在源以下三个距离处测量了完全密度n和电子温度T-e分布。源内的等离子体也用一个特殊的探针测量，甚至在天线下面。那里的密度比预期的要低，因为产生的等离子体立即喷射出来，充满了实验室内。螺旋比电感耦合等离子体（没有b场）的优势随着射频功率的增加而增加。在高b场，可以看到Trivelpiece-Gould模式的边缘电离。这些结果对于等离子体刻蚀和沉积的多管、大面积螺旋源的设计是有用的，因为这些问题不能仅靠理论预测。(C) 2012年美国物理研究所。[http://dx.doi.org/10.1063/1.4754580]
A small helicon source is used to create dense plasma and inject it into a large chamber. A permanent magnet is used for the dc magnetic field (B-field), making the system very simple and compact. Though theory predicts that better antenna coupling will occur at 27.12 MHz, it was found that 13.56 MHz surprisingly gives even higher density due to practical effects not included in theory. Complete density n and electron temperature T-e profiles are measured at three distances below the source. The plasma inside the source is also measured with a special probe, even under the antenna. The density there is lower than expected because the plasma created is immediately ejected, filling the experimental chamber. The advantage of helicons over inductively coupled plasmas (with no B-field) increases with RF power. At high B-fields, edge ionization by the Trivelpiece-Gould mode can be seen. These results are useful for design of multiple-tube, large-area helicon sources for plasma etching and deposition because problems are encountered which cannot be foreseen by theory alone. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4754580]