INVESTIGATION OF INHOMOGENEITIES IN A-SIN(R)-H ALLOYS BY INFRARED-SPECTROSCOPY

Frequencies of subbands in the Si-H stretching absorption band of a-SiN(r):H alloys were calculated by means a chemical induction model for a wide range of nitrogen and hydrogen concentrations ([N]/[Si] from 0 to 1.33 and [H]/[Si] from 0 to 0.6). Films of a-SiN(r): H with 0 less-than-or-equal-to r less-than-or-equal-to 0.40 were obtained by glow discharge decomposition of SiH4 + NH3 + H-2 mixtures at temperature of 220-degrees-C, pressure of 0.37 Torr and power density of 0.3 W/cm2. Decomposition of SiH stretching absorption band into four peaks corresponding to HSi3-nNn structures with n = 0, 1, 2, 3 and comparison of peak frequencies with values calculated with the chemical induction model allow one to detect the local environment of Si-H bonds.