Characterization of wide bandgap thin film growth using UV-extended real time spectroscopic ellipsometry: Applications to cubic boron nitride

Boron nitride (BN) films with high cubic content were deposited using pulsed dc sputtering of a B4C target and rf biasing of the substrate. The film growth was characterized using UV-extended real-time spectroscopic ellipsometry. A three-layer model with constrained thickness evolution was used to characterize the growth of BN films on c-Si substrates. This model includes: (i) an initial hBN layer; (ii) a hBN + cBN mixed-phase interface layer; and (iii) a cBN layer. The detailed layer evolution was obtained as a function of the substrate bias (V_avg) used to grow the BN films under steady-state conditions. These results showed a minimum in the thicknesses of the hBN and mixed-phase interface layers thus identifying an optimum substrate bias for cBN nucleation and growth under the deposition conditions used here. © 2002 Sage Publications.