The control of film stress using ionised magnetron sputter deposition

Ion assisted deposition techniques offer the control of energetic surface bombardment during film growth. There have been many studies of intrinsic stress in sputtered films, and it has been found that the total energy input at the growing film plays a crucial role in stress development. Using magnetron sputter deposition, with a built-in RF coil to generate a high-density inductively coupled plasma confined close to the substrate, we have studied the stresses of deposited films. It is possible to draw a sufficient ion flux, containing ions of the sputtering gas and the depositing species, to the substrate. Therefore, this process is able to provide controllable energetic ion bombardment, in terms of both flux (by RF power) and energy (by substrate bias), during film growth. Film stress was measured, using a substrate curvature technique, as a function of several deposition parameters including the bombarding ion flux, ion incident energy, ionisation fraction of depositing atoms and operational pressure. By controlling the ion flux and ion incident energy, we are able to control the film stress. (C) 1999 Elsevier Science S.A. All rights reserved.