ISSN Online: 2377-424X
ISBN Print: 978-1-56700-474-8
ISBN Online: 978-1-56700-473-1
International Heat Transfer Conference 16
HIGH THERMAL CONDUCTIVITY THIN FILM FOR HEAT SPREADING ENHANCEMENT IN MICROELECTRONIC MEASURED USING SHORT PULSED PHOTOTHERMAL TECHNIQUE
Sinopsis
Due to increase in density and performance of electronic devices, heat dissipation in multilayer assembly has to
be managed carefully especially close to the heat sources. Heat transfer can be improved with the implementation
of a heat spreader such as a thermally conductive thin film. However, their elaboration is critical since the obtained
thermal conductivities are very sensitive to synthesis condition and growth mechanism of thin film which involve
various crystalline qualities and microstructures. Pulsed photothermal technique is one of the few techniques that
can provide thin film high thermal conductivity measurement. Nevertheless, due to the very small involved time
scales about 50 to 100 ns for heat transfer inside such a thin film, one has to be very careful in order to avoid
several bias during parameter estimation. This work will present the effect of various heat flux evolution showing
that traditional use of a Dirac function in the thermal model based on quadrupole technique, and which is used for
the parameter estimation, induces noticeable bias in the estimated thin film thermal conductivity reaching up to
20% for a thin film of 180 W.m-1.K-1 k value. This study was performed using simulated data computed
using finite element software and considering aluminum nitride thin films deposited on glass or sapphire
substrates. Finally, a high thermal conductivity values around 143 W.m-1.K-1 was measured for a 2 μm aluminum nitride thin film deposited on a sapphire substrate using a magnetron sputtering technique.