Effects of periodic axial magnetic field on photoresist ashing in an inductively coupled plasma

초록

Low frequency(< 100 Hz) weak magnetic field(< 20 gauss) is applied axially to an inductively coupled oxygen plasma(ICP), and its plasma characteristics are monitored by optical emission spectroscopy and Langmuir probe. It is found that periodic magnetic field enhances ashing rate y 13% and improves its uniformity to 1% over 8" wafer. From electron energy distribution function, both low and high energy electrons are identified and relative abundancy is found to be controlled by the applied frequency.