Selective synthesis and characterization of HYSYCVD-Si2N2O

Abstract In this work, stoichiometric silicon oxynitride (Si 2 N 2 O) has been successfully synthesized using a selective approach via hybrid precursor system-chemical vapor deposition (HYSYCVD). The deposited oxynitride phase has the following structural parameters: formula sum: Si 8.00 N 8.00 O 4.00 ; formula mass: 400.7352 g mol −1 ; density: 2.8010 g cm −3 ; orthorhombic structure with lattice parameters (A): a  = 8.898, b  = 5.495, c  = 4.858. The optimum conditions for maximizing the amount of Si 2 N 2 O are as follows: SiC p /Si p substrate with 60% porosity, UHP-N 2 at a flow rate of 10 cm 3  min −1 , and no use of diluent. According to ANOVA, flow rate of nitrogen precursor is the processing parameter that most significantly affects Si 2 N 2 O formation, with a relative contribution of 46%, followed by the type of nitrogen precursor (44%). Regarding the best nitrogen precursor, thermodynamic predictions on the formation of Si 2 N 2 O are in good agreement with ANOVA results. Analysis by SEM shows that Si 2 N 2 O is deposited into the preforms as rough fibers, snow-like fibers and spheres.