Reconstruction of interfacial thermal transport mediated by hotspot in silicon-based nano-transistors

•Interfacial thermal transport mediated by hotspot in individual silicon-based transistor and heterojunctions was investigated based on BTE and e-MC.•Strong phonon nonequilibrium effect exists in the hotspot and LO mode phonons dominate the lattice temperature rise.•Reverse heat flux same as the temperature gradient appears near the hotspot due to the reflection of phonons at interface.•Interface phonon modes provide additional heat conduction channels in heterojunction under hotspot.