Influence of adsorption kinetics on stress evolution in magnetron-sputtered SiO_2and SiN_x films

摘要

An in situ multi-beam optical sensor system was used to monitor and analyze the force per unit width (F/w) and stress evolution during several stages in magnetron-sputtered SiO_2 and SiN_x films. Stress was observed to relieve quickly after interrupt and recover rapidly after growth resumption in both films. Stress relief was reversible in SiO_2 film but partial reversible in SiN_x 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 SiO_2 film because of the stable chemical structure. The relationship between adsorption kinetics and films' mechanical behavior is revealed.