Compact Multitube Helicon Source with Permanent Magnets

In spite of their efficiency, helicon sources are not readily adopted by industry because they require a large, heavy electromagnet and its power supply. Annular permanent magnets can create the B-field compactly and cheaply, but only if the plasma is placed outside the magnet in its remote field, so that the internal field lines do not carry the plasma into the wall. An 8-tube array of such sources has been constructed and tested. The size and shape of each tube was optimized by computation. The source can be extended to provide uniform densities of order 10$^{12}$ cm$^{-3}$ over an arbitrarily large substrate. This source, which requires only six inches of height above the processing chamber, would be useful for web-coating, optical coating, and etching of flat-panel displays and solar cells.