Characterisation of high thermal conductivity thin-film substrate systems and their interface thermal resistance

Abstract

This paper characterises the high thermal conductivity thin-film substrate systems and the interface thermal resistances between the films. First, three-omega (3ω) method was proposed and verified, obtaining a reliable thermal conductivity measurement at shallow thermal-penetration depths. The method was then applied to a thin-film/substrate system to identify the individual thermal conductivities. The interface thermal resistance between the thin films was then successfully characterised with the aid of theoretical modelling and experimental measurements. As an example of the method application in the IC industry, the AlN/Si systems were investigated. The study identified that the thermal conductivity of the 2μm-thick AlN film in an AlN/Si system is 172.1W/mK and the AlN/Si interface thermal resistance is 1.796×10−9m2K/W.