Room temperature growth of cubic boron nitride

Boron nitride thin films were deposited at room temperature with various io n energies by mass selected ion beam deposition on cubic boron nitride (c-B N) previously nucleated on Si (100) substrates at a higher temperature. Sel ective area diffraction, electron energy loss, and infrared spectroscopy re sults reveal continued growth of the cubic phase. The reported temperature threshold of about 150 degrees C for c-BN film formation is therefore unmis takably related to the initial nucleation of c-BN, whereas the growth of c- BN appears to be temperature independent. The latter is in accordance with predictions of the cylindrical thermal spike growth model recently proposed by our group. (C) 1999 American Institute of Physics. [S0003-6951(99)00211 -9].