Atomic bonds in boron carbon nitride films synthesized by remote plasma-assisted chemical vapor deposition

摘要

Boron carbon nitride (BCN) films are synthesized by remote plasma-assisted chemical vapor deposition (RPCVD) method. The present experimental apparatus is featured by introducing BCl_3 gas near the substrate without mixing to plasma consisting of N_2 and CH_4 gases. Two sample groups of the BCN films are prepared. One is grown with various CH_4 flow rates, and another is grown with various BCl_3 flow rates. The composition ratio of the constituent atoms, atomic bonds and optical bandgap are investigated. C composition ratio of the BCN film increases with increasing CH_4 flow rate, leading to a reduction in the optical bandgap with increasing C composition ratio. On the other hand, it is found that no significant variation in the composition ratio occurs for the BCN films grown with various BCl_3 flow rates and that the optical bandgap decreases with increasing BCl_3 flow rate. This behavior of the optical bandgap is related to a change of the atomic bonds in the BCN film grown with various BCl_3 flow rates.