Evaluation of SF6 reactive ion etching performance with a permanent magnet located behind the substrate based on a simple design concept

Reactive ion etching performance with a permanent magnet located behind the substrate was evaluated in a compact vacuum chamber configuration with 38 mm inner diameter. This study presents a simple design concept for a compact SF6 plasma reactor that has high-density plasmas radially compressed by a magnetic field. The magnetic field lines, which are created by a solenoid coil and permanent magnet, effectively transport ions to the substrate located downstream from the plasma source, and thereby reduce losses of plasma to the radial boundaries of the compact chamber. An etching rate of 6.0 m/min was obtained with input RF power of 500 W, a pulsed plasma discharge with duty ratio of 10% and chamber pressure of 0.2 Pa. The etching rate achieved in the present study was increased more than tenfold, in comparison with our previous study, performed under similar conditions but without a permanent magnet located behind the substrate.