A multi-tube helicon source

Summary form only given, as follows. A seven-tube array of helicon sources is used to create a large-area plasma for semiconductor processing. Each source is 5 cm in diam with a helical antenna and a magnetic field of 0-100 G. Above a certain threshold power, the RF match circuit distributes the power equally to all the tubes. The plasma is injected into a 50-cm diam magnetic bucket, and the density uniformity is measured at various distances downstream from the source. Experiments were done in A and Cl and at frequencies of 13.56 and 27.12 MHz. Initial trials gave fairly uniform plasmas over a 30 cm diameter, and continuing work will optimize the tube diameter and spacing, the antenna configuration, and the magnetic field shape.