Published online by Cambridge University Press: 01 February 2011
We present a theoretical investigation of the effects of dislocations, impurities and dopants on the thermal conductivity of GaN layers. It is shown that the experimentally observed decrease of the room-temperature thermal conductivity with increasing doping density is a result of enhanced phonon relaxation on silicon dopant atoms. Scattering of acoustic phonons on free carriers plays a relatively minor role in GaN. The functional dependence of the thermal conductivity on doping density is in good agreement with experiment. A developed model can be used for thermal budget calculation in high-power density GaN devices.