Investigations on the energy influx at plasma processes by means of a simple thermal probe

The total energy flux for three different plasma process devices has been measured by means of a simple thermal probe. The procedure is based on the measurement of temporal slope of the substrate temperature during the plasma process. A substrate dummy which is thermally isolated is inserted into the plasma at the substrate position. The thermal probe presented allows for sensitivities of approximately 10(-3) J/s and it can be simply used under typical plasma environments, e.g.: for a-C:H film deposition by magnetron sputtering of a graphite target in Ar/H-2 (#1); in an RF plasma which is used for the modification of micro-disperse powder particles (#2); and nitrogen recombination on metal surfaces in the afterglow of an electron cyclotron resonance (ECR) discharge (#3). Measured specific energy fluxes are 0.03 J/cm(2) s for carbon film deposition and 0.08 J/cm(2) s for sputtering of molybdenum films which are obtained in #1. In #2 the specific energy input is in the range of 0.01 J/cm(2) s, while under the conditions of #3 values of approximately 0.5 J/cm(2) s have been determined. The measured values are compared with the energetic contributions which are calculated on the basis of the relevant plasma parameters. (C) 2000 Elsevier Science B.V. All rights reserved.