Electron cyclotron resonance plasma source by using Ku-band traveling-wave tube amplifier for broad ion-beam processing

A new electron cyclotron resonance (ECR) plasma source has been developed for broad ion-beam processing. A Ku-band traveling-wave tube amplifier (11–13 GHz) is adopted to generate high-density plasma under low-pressure conditions. An eight-pole magnetic field is selected to improve good uniformity and plasma confinement. The ECR zone for 11 GHz microwaves, i.e., 0.393 T, is formed within 6.5 mm of the inner wall of a chamber. The ECR plasma is generated by low microwave power (∼200 W). The radial profile of plasma density and electron temperature is measured with a Langmuir probe. The plasma density is approximately 3×10¹⁷ m^-3 at the microwave power of 200 W. The uniformity of the density is within ±12.6% over 140 mm in diameter.