Silicon nitride films have been grown by hot-wire chemical vapor deposition and film properties have been characterized as a function of SiH4/NH3 flow ratio. Quadrupole mass spectrometry measurements revealed that NH3 should be present in large excess relative to SiH4 (<10), due to its lower decomposition probability on the wire. Silicon nitride films were produced with refractive indices ranging from 1.8-2.5 and H-content from 9-18 atomic % as the flow ratio increased from 1% to 8%. Fourier Transform Infrared Spectroscopy revealed a change from predominantly N-H to Si-H bonding as the flow ratio increases beyond 6%. Subsequent annealing studies showed different kinetics for H release from Si versus N. Films grown with a low SiH4/NH3 ratio were found to oxidize readily (23 atomic %), while larger ratios yielded no oxygen incorporation.