| 摘要 |
<P>PROBLEM TO BE SOLVED: To confine a plasma in a way that deposits due to chamber wall etching or byproduct deposits due to chamber wall etching can be reduced. <P>SOLUTION: First, an annular plasma confinement ring is placed that has a gap distance with the chamber wall at between about 0.8 inch to about 1.5. Second, plasma is confined by the impedance confinement scheme of reducing a voltage supplied to the top electrode by a voltage ratio during plasma processing and supplying the remaining voltage supplied to the top electrode at a negative phase at the substrate support or the substrate. The voltage ratio is adjusted by changing the impedances of the substrate support and a dielectric seal surrounding the top electrode. The amount of plasma got attracted to the grounded chamber wall is reduced, thereby improving plasma confinement. The method of plasma confinement can be improved by using either the described annular ring, the impedance confinement scheme or a combination of both. <P>COPYRIGHT: (C)2007,JPO&INPIT |
