MULTICUSP ELECTRON-CYCLOTRON-RESONANCE PLASMA SOURCE WORKING WITH MICROWAVES RADIALLY INJECTED THROUGH AN ANNULAR SLIT

A new-type electron-cyclotron-resonance (ECR) plasma source has been d eveloped for materials processing. The reactor employed magnetic multi cusp fields and microwaves radially injected through an annular slit; this configuration yielded stable, uniform discharges without contamin ation of the microwave entrance window by sputtered particles. Electro static probe and optical emission measurements were made to obtain the plasma properties in Ar. These measurements showed that high-density, uniform plasmas were produced by optimizing the width of the annular slit. Moreover, the electron temperature exhibited its strong peak aro und the ECR zone near the chamber wall. A simple model indicates the m echanisms responsible for the plasma uniformity obtained: the plasma w as dominantly produced around the ECR zone, and then diffused preferen tially toward the center of the chamber because of strong magnetic fie lds generated near the wall surface.