ISSN Online: 2377-424X
International Heat Transfer Conference 12
Phonon Heat Conduction from Nanoscale Hotspots in Semiconductors
Sinopsis
Nanometer-scale phonon hotspots with highly non-equilibrium distributions of optical phonons are formed in semiconductor devices by the scattering of high-energy electrons. When the mean free path of acoustic phonons is larger than the size of the hotspot,heat conduction from the hotspot is impeded by the weak anharmonic coupling between the optical and acoustic modes. This phenomenon is explored here using the phonon
Boltzmann transport equation (BTE) under a two-fluid approximation, which predicts an extra resistance that scales with the square of the ratio of mean free path to an effective hotspot dimension. The predictions are consistent with low-temperature data based on heating and electrical-resistance thermometry along a doped region in a suspended silicon membrane. The two-fluid resistance investigated here is larger than the resistance associated with ballistic phonon emission. This work is improving the constitutive modeling of heat flow in deep sub-micrometer semiconductor devices.
deep sub-micrometer semiconductor devices.