High rate sputtering type ECR plasma technique with electric mirror

It is difficult for a conventional ECR sputtering apparatus to prepare films at high deposition rates under a low gas pressure without damage to the dense plasma. In the present study, a new ECR sputtering apparatus using an electric mirror is developed. Both insulator and conductor film can be continuously prepared at high deposition rates by this method. The new sputtering type ECR microwave plasma deposition apparatus is outlined first. Its cavity has the resonance shape of a TE113 standing wave mode in a vacuum at the 2.45 GHz microwave frequency. The plasma generated in the cavity is accelerated through a hole. A magnetic field of 875 G is applied in the resonance cavity. Microwave power is introduced obliquely or perpendicularly into the cavity through a vacuum microwave waveguide connected to the cavity's side-wall. A microwave pressure window is provided at a place which cannot be directly viewed from either target, to prevent contamination of the window by neutral sputtered particles. High-density plasma is obtained not only through direct collision ionization between electrons and neutral particles but also through nonlinear interaction between the electron beam and the plasma. (N.K.)