A New High-Density Plasma Etching System Using A Dipole-Ring Magnet

Abstract

A new high-density plasma etching system has been developed using a dipole-ring magnet (DRM). The system utilizes a parallel magnetic field up to 600 G with excellent uniformity extending over 250 mm in diameter. The nonuniformity of plasma was compared with that of a conventional permanent-magnet-enhanced plasma using a gate oxide integrity test. The plasma generated using DRM produced no gate oxide degradation, while the conventional magnetron plasma produced some gate oxide degradation under the most highly accelerated conditions. Si etch rate is shown to depend strongly on magnetic field strength, increasing from 1.3 µm/min at 120 G to 2.1 µm/min at 600 G.