Chemical vapor deposition boron carbo–nitride deposited using dimethylamine borane with ammonia and ethylene

Amorphous boron carbo–nitride films, $BCxNy$⁠, $(0.05⩽x⩽1.51,0.05⩽y⩽0.67)$⁠, were deposited on $SiO2$ at $360°C$ and $1Torr$ using dimethylamine borane $[NH(CH3)2:BH3]$ with ammonia and/or ethylene. The film composition could be controlled by varying the flow of ammonia and ethylene. X-ray photoelectron spectroscopy indicated a change in bonding environments, increasing the B–N bonding with the addition of ammonia and increasing B–C and C–C bonding with the addition of ethylene. The film dielectric constant, $k$⁠, was 4.62 without coreactant, decreased to 4.11 by adding ammonia and 3.66 upon adding ethylene. The index of refraction ranged from 2.069 to 1.826 with correlation to $k$ depending on the coreactant added. The root mean square surface roughness ranged from $0.30to0.65nm$⁠, increasing with the use of ethylene. A $1μm$ film deposited at $3.60°C$ using $C2H4$ had a hardness of $8.7GPa$ and modulus of $71.3GPa$⁠.