THERMAL POWER AT A SUBSTRATE DURING ZNO-AL THIN-FILM DEPOSITION IN A PLANAR MAGNETRON SPUTTERING SYSTEM

In a balanced magnetron sputtering system the thermal power at a subst rate has been determined from the temperature change nf the substrate when the plasma is switched nn Using thp temperature as a function of the potential of a probe, the calorimeter has been calibrated absolute ly. A heat input equivalent of about 10 eV per electron has been deter mined for a dc discharge, The results for the total thermal power at t he substrate are compared with values published by other groups for si milar discharge systems, The contributions of different kinds of parti cles are discussed. For the dc discharge at a discharge power of 50 W and a pressure of 0.8 Pa, a thermal power of 15.6 mW cm(-2) has been f ound which is mainly produced by particles other than the plasma ions. It can be concluded from the increase of the thermal power with decre asing pressure that bombardment by particles originating from the targ et is the main source of the substrate heating, In an rf discharge the ion energy is two times and the flux density is nearly three times hi gher than in a dc discharge. Here the dependence of the thermal power on pressure is only weak and mainly the plasma ions transport the powe r to the substrate. (C) 1997 American Institute of Physics.