Effect of Plasma Protection Net on Crystal Orientation and Residual Stress in Sputtered Gallium Nitride Films( Materials Evaluation by X-ray and Neutron Diffractions)

Abstract

X-ray diffraction was carried out in order to investigate crystal orientation and residual stress in gallium nitride (GaN) films deposited on a fused quartz substrate by radio frequency (RF) planar magnetron sputtering with a net to protect against plasma exposure. GaN films were deposited at constant gas pressure, constant input power, and various substrate temperatures. The following results were obtained: (1) GaN film of good crystal orientation can be deposited by RF sputtering; (2) in all films deposited at high substrate temperature, the c-axes of GaN crystals were oriented normal to the substrate suffice; (3) crystal orientation was good in films deposited at high substrate temperature Ts > 573 K, but film deposited at Ts = 873 K peeled from the substrate; (4) good crystal orientation was attained in films deposited by sputtering with the fine mesh to protect against plasma exposure; (5) compressive residual stress was found in film deposited at low Ts below 573 K; (6) compressive residual stress was found in films deposited by RF sputtering with the plasma protection net.