Thermal Conductivity Measurements of Thin Aluminum Layers Using Steady State Joule Heating and Electrical Resistance Thermometry in Suspended Bridges

Thin metallic film layers are extensively used as the constituents of the micro-devices. The reliability of these devices, therefore, strongly depends on the thermal behavior of such film layers. Aluminum thin film layers are of particular interest in this respect. The lateral thermal conductivity of the aluminum film layers is measured, using the steady state electrical Joule heating and electrical resistance thermometry technique. Aluminum suspended microbridges of identical thicknesses (500 nm) and variable widths (16 to 18 μm) and/or lengths (200 to 500 μm) are fabricated, using conventional microfabrication processes. The lateral thermal conductivity of the 500 nm thick Aluminum film layer was found to be k = 174 ± 13 Wm⁻¹ K⁻¹, at room temperature (300 K).