Phonon-Dominated Mobilities for Carriers in a Diamond Field Effect Transistor With a cBN Overlayer

In this letter we investigate phonon-dominated mobilities for carriers in a diamond field effect transistor with a cubic Boron Nitride (cBN) overlayer. We investigate the intra-subband scattering due to interaction of electrons with acoustic phonons, treated properly as quantized surface acoustic Rayleigh waves, and include, for the first time, the interaction with remote polar phonons originating in the cBN overlayer. We conclude that the surface acoustic phonon scattering is the dominant mechanism limiting the mobility of electrons for temperatures below 375 K.