A selective range of hydrated silicon oxynitride thin films (SixOyNz:H) have been characterized in terms of their stress, hardness, and modulus in order to mechanically qualify them for use as an encapsulation layer for memory devices (e.g., Flash and EPROM memories). These films are analyzed by RBS and HFS for stoichiometry. The films exhibited stress values between 1.86 x 109 to -3.54 x 109 dyne/cm2 and showed a linear correlation with the hydride ratio (N-H/Si-H). An Ultra Micro-Indentation System (UMIS) measured hardness values between 10.5 GPa to 16.2 GPa while the elastic modulus varied between 119.1 to 141.2 GPa. The monatomic increase of modulus with hardness is attributed to increased amounts of nitrogen and nitrogen hydride bonding in the silicon oxynitride samples.