Growth of Single Crystal Cubic Boron Nitride Films

The purpose of this proposed program is to grow single crystal cBN films on compatible substrates. Currently, single crystal cubic boron nitride (cBN) can only be grown by the high pressure/high temperature method, which limits the size to a few millimeters. In spite of the small size and poor quality, p-n junctions have been made by the HP/HT method and W detectors and W emitters have been built. CVD methods have produced only poor quality polycrystalline mixed cubic and hexagonal phase which is unsuitable for electronic applications. Availability of cubic boron nitride films in R&D and production quantities for development of UV LEDs, UV detectors, high temperature devices and high frequency-high speed devices and ICs. cBN is also of interest for its potential to make heterostructures with diamond, which could lead to n-type diamond having a high carrier concentration and a high mobility. In addition to electronic applications, cBN is desirable for high speed tool bits to cut ferrous metals.