Effect of a plasma protection net on residual stress in AlN films deposited by a magnetron sputtering system

Abstract

Crystal orientation and residual stress development in AlN films deposited on borosilicate glass (the thermal expansion coefficient of which is nearly equal to that of AlN) substrates were investigated by X-ray diffraction method. The AlN films were prepared by a conventional planar magnetron sputtering system with a plasma protection net under the condition of constant substrate temperature and various nitrogen gas pressures between 0.8 Pa and 13 Pa. We found that the residual stresses show the same qualitative tendency against the nitrogen gas pressure independent of the use of the plasma protection net. Large tensile residual stress was observed at high nitrogen gas pressure and large compressive residual stress was observed at low gas pressure. When the plasma protection net was used, residual stresses in the AlN film were shifted to the compressive side.