Sputtering technique has been used widely due to the high performance of the films prepared. As the important materials widely used in optical film sciences, functions of SiO2 and SiNx films are influenced markedly by the stress state during growth. Consequently, it is important to study the mechanical behavior in magnetron-sputtered SiO2 and SiNx films.
Researchers at Shanghai Institute of Optics and Fines Mechanics (SIOM/China) studied the stress evolution during and after deposition of magnetron-sputtered SiO2 and SiNx films using in situ wafer curvature measurements. They found that adsorption kinetics has a significant influence on stress evolution of films. [JOURNAL OF APPLIED PHYSICS.114(3),034305,2013]
Stress relief was reversible in SiO2 film but partial reversible in SiNx film. Stress relief results from both physical and chemical adsorption. Stress recovery is caused by physical desorption. And chemical adsorption results in an irreversible stress relief component. No chemical adsorption occurs in SiO2 film because of the stable chemical structure. The relationship between adsorption kinetics and films' mechanical behavior is revealed.
