High Rate Reactive Ion Etching Using Collimated Beam Produced by 10-3 Torr Magnetron Discharge

A new high rate RIE technology using a magnetron discharge in the low pressure of 10-3 Torr has been developed. A racetrack type permanent magnet, which is set at an anode, allows an intense plasma generation near a wafer surface on a cathode. The magnetic field divergence to the cathode provides uniform plasma intensity, leading to the uniform etching. The lower pressure discharge, at which ion collisions are reduced within the sheath, generates normally collimated ions. Thus, the directional etching, which does not depend so much on the aspect ratio variations, has been established.