Chemical bonding investigation of amorphous hydrogenated Si–N alloys deposited by plasma immersion ion processing

Abstract Amorphous hydrogenated Si–N (a-SiN x :H) alloys were deposited by plasma immersion ion processing using a working pressure of 1.3 Pa of mixtures of SiH 4 and N 2 . Films with N/Si ratios from 0.6 to 1.2 were obtained, as determined by Rutherford backscattering spectrometry (RBS) and elastic recoil detection analysis (ERD). A fixed total H content of 9 at.% was observed in all films. Chemical bonding was investigated by infrared, Raman and X-ray photoelectron (XPS) spectroscopies. These techniques revealed a complex Si chemical environment that evolves towards that of Si 3 N 4 for higher N/Si ratios. This evolution was correlated with the increase of film hardness.