Microwave magnetoactive plasma source

A microwave magnetoactive plasma source working in the ECR regime and suitable for the deposition and etching of thin films was constructed. The discharge chamber is a short conically closed quartz glass tube 90 mm in diameter, fixed to the flange of the processing vacuum chamber into which the plasma stream flows. It is inserted into a cylindrical waveguide 100 mm in diameter and a coil generating a stabilized magnetic field of an induction B0 up to 0.15 T. For the generation of microwaves a magnetron with a frequency of 2.45 GHz was used; the microwave power was up to 100 W. The conditions needed for the discharge ignition are given, and the basic plasma characteristics measured by an electrostatic probe on the source axis in the substrate region are presented in dependence on pressure, field strength and microwave power both for hydrogen and argon. At a hydrogen pressure in the vacuum chamber of 0.5 Pa, plasma density of 10-9 cm-3 and electron energy less than 4 eV were achieved. (author) 8 figs., 9 refs