Thin film thermal conductivity metrology using photoluminescence of quantum dots

Studying thin film thermal conduction is important in the development of many heat related sensors, actuators and microsystems. Emerging non-contact metrologies of membrane thermal conductivity show several advantages when devices are scaling down or novel materials are utilized. In this paper, a method to evaluate membrane thermal conductivity is presented using quantum dots as temperature markers. As an example, the thermal conductivity of 290nm-thick crystalline silicon thin film is measured as 106±10W/(m·K). Compared to conventional methods, the features of this method, like fine spatial resolution and non-contact temperature probe, bring the measurement robustness against ambient disturbance and the reduction on measurement system error. Furthermore, this metrology is eligible for thin films of other materials.