MEASUREMENT OF THERMAL CONDUCTIVITY OF SILICON NITRIDE THIN FILMS

Heat transport characteristics of nano/microscaled materials such as thin films show different behavior from those of bulk materials. In this study, measurement of thermal conductivity of dielectric thin films has been conducted. The 3 omega method has been suggested for the measurement technique. Via this method, thermal conductivities of silicon nitride thin films were measured with various thicknesses such as 30nm, 50nm, 70nm, and 100nm thick. The 3 omega method is an AC modulating technique which has advantage of minimal loss of radiation due to very small temperature oscillation. Silicon nitride thin films were deposited by plasma enhanced chemical vapor deposition (PECVD) and the gold heater which works as a heater and a sensor simultaneously was deposited on silicon nitride film by thermal evaporation for 100nm. Also, 10nm of Cr layer was deposited by thermal evaporation for adhesion layer. The measuring temperature was in a range of 50 to 150℃. Experimental results show that the measured thermal conductivities of the thin films show smaller value than that of bulk material. Also, the results tend to increase with temperature as well as thickness.