Nanostructures of mixed-phase boron nitride via biased microwave plasma-assisted CVD

Abstract

Boron nitride films and nanostructures are deposited by the reaction of B2H6 and NH3 in H2 via biased microwave plasma-assisted chemical vapor deposition. One-dimensional boron nitride nanostructures (BNNSs) are observed on the BN layers by the processing of diamond/BN multilayer under ion-bombardment and plasma etching. At a substrate bias of −100 V, the morphologies of the BNNSs evolve from dense film to nanocorns to nanotips, when the number of the diamond/BN bi-layer increases. Various phases of boron nitride including amorphous-BN, hexagonal h-BN, turbostratic t-BN, rhombohedral r-BN, explosion E-BN, wurtzitic w-BN and cubic c-BN are detected in the BNNSs. The BN nanotips observed are considered to result from the tip structure growth from the combined effects of ion bombardment and plasma etching.