Automatic Langmuir probe measurement in a magnetron sputtering system

The electron temperature, ion density, plasma potential and magnetic field are measured in a plasma produced by a magnetron sputtering device. The magnetic field has been mapped by measuring the axial and radial components with Hall probes. The plasma parameters have been measured by a diagnostic system consisting of several Langmuir probes with different collecting areas that can be positioned by a linear translator. The automatic analysis system allows one to take into account non-saturation of the ion current due to sheath thickness variation. The Langmuir probes have been used in various conditions of magnetic field and source power with a gas filling pressure of 1 Pa. It has been found that the diagnostic system gives reliable measurements of the plasma parameters in static and inhomogeneous magnetic fields. (C) 1999 Elsevier Science S.A. All rights reserved.