Stress control of a-SiC films deposited by dual source dc magnetron sputtering

In the present paper, we show that a-SiC films deposited from two independent Si and graphite magnetron sputtering sources have small tensile stress of ∼100 MPa without post-deposition annealing. Our sputtering apparatus has a rotation substrate holder that is designed to move to the front of individual targets alternately. In this experimental geometry, the relaxation period, when no deposition is made, must be present during sputtering. The presence of this relaxation period is found to be effective to change the compressive internal stress of deposited films into tensile direction. We have also succeeded to fabricate free-standing a-SiC soft X-ray filter with the thickness of 100–600 nm. The transmission spectra of these filters for soft X-ray beam showed good agreement with calculated ones.