上海科技大学知识管理系统

Introducing hydrogen bonds into the structure of amorphous silicon nitride (a-SiNx:H) a-SiN x :H) is attractive for dielectrics seeking extremely low thermal conductivity. Yet, experimental explorations of enhancing diffuson scattering are still insufficient. Here, a-SiN 0.91 :H films containing (25 +/- 5)% hydrogen as well as control samples of hydrogen-free a-SiN 0.96 films were characterized using microbelt thermal bridge devices. The capability of employing a transfer length method to extract intrinsic thermal conductivity was demonstrated. Unusual thermal contact resistances and diffuson transfer lengths were corroborated, which provided evidence of diffuson crowding phenomena at bridge-end homojunctions. Two distinct features, including diffuson population-dictated thermal conductivity at low temperature and diffuson scattering-dominant thermal conductivity at high temperature were revealed. The effect of a hydrogen heavily-incorporated structure showed that room temperature thermal conductivity of a-SiN 0.91 :H is largely suppressed to 0.8 . 8 +/- 0.1 . 1 W/(m K), / (m K), compared with 1.8 . 8 +/- 0.3 . 3 W/(m K) / (m K) of hydrogen-free a-SiN 0.96 .