Multipole confined diffusion plasma produced by 13.56 MHz electrodeless source

Abstract

An inductively coupled rf plasma source is shown to produce a large uniform diffusion plasma at low pressures in a reactor surrounded externally by small magnets arranged to produce cusp fields at the walls. Electron densities of >1011 cm−3 can be produced at pressures of <10−3 Torr argon with 800 W input power. With SF6 ion currents of 0.5 mA cm−2 uniform to ±1.5% over 15 cm diameter have been measured at 6×10−4 Torr and 400 W.