MAGNETIC MULTIPOLE-BASED REACTIVE ION ETCHING REACTOR

The addition of a simple inexpensive magnetic multipole to a parallel plate triode results in a magnetic enhanced etch reactor configuration that has impressive low pressure characteristics. The multipole electrode which is in the form of a cylindrical multipolar bucket, open at both ends, is added to the powered electrode of the triode being employed as a plasma etching system. The multipole becomes, in effect, an extension of the ground shield, surrounding either electrode. The resulting electrode configuration produces an extremely uniform, dense plasma at pressures as low as 2-3 X 10(-4) Torr. The effect of the magnetic enhancement (electron containment, uniformity profile modification, and low substrate bias) is particularly pronounced at lower pressures. Significant improvement over existing triode schemes is obtained using the grounded cylindrical multipolar bucket as an extension of the ground shield of the driven electrode (not the substrate electrode). This system is considerably simpler than dual frequency driven trielectrode systems since it uses 13.56 MHz excitation of both electrodes.