Effect of sputtering gas pressure and nitrogen concentration on crystal orientation and residual stress in sputtered AlN films

The crystal orientation and residual stress in sputtered AIN films were investigated by X-ray diffraction. The AIN films were deposited on a glass substrate by direct current (DC) and radio frequency (RF) planar magnetron sputtering system at mixed gas of argon and nitrogen under various sputtering gas pressures (P) and nitrogen concentrations (C-N). The following results were obtained: (1) the degree of the c-axis orientation of AIN films deposited by RF sputtering was superior to those produced by DC sputtering; (2) the degree of the c-axis orientation of AIN films was improved with decreasing P and increasing C-N; (3) in-plane large compressive stress was obtained at low P, and in-plane tensile stress was obtained at high P (P > 1.3 Pa); (4) film produced by DC sputtering at low P (P < 1 Pa) extensively included micro-cracks; and (5) in-plane tensile stress was obtained at low C-N and large compressive stress was obtained at C-N (C-N > 40 /N). (C) 2002 Elsevier Science Ltd. All rights reserved.