Synthesis of High-Quality Cubic Boron Nitride Films By Chlorine-Assisted Chemical Vapor Deposition

In this project we will study the chemical vapor deposition of cubic boron nitride (cBN) films in a new gas system of BCl3+N2+H2+Ar+He. It is expected that the introduction of chlorine chemistry in the growth atmospheres enables the formation of cBN phase at reduced ion bombardment energies and thus leads to cBN growth with improved crystallinity. The proposal is based upon a new route we are using and the mechanism recently proposed by us for the growth of cBN films in halogenated plasmas. The influence of growth parameters such as reactive gas composition, pressure, substrate temperature, and substrate bias, on the structure, orientation, phase composition, crystal size, defect density, and stress in the cBN films will be systematically investigated; and the growth mechanism of cBN films with the assistance of chlorine chemistry will be further studied.