Design of integrated thin film coolers

Thin film coolers can be monolithically integrated with optoelectronic and high-speed electronic components. Important parameters in the design of such coolers are investigated theoretically and experimentally. A three-dimensional finite element simulator (ANSYS) is used to model self consistently thermal and electrical properties of a complete device structure. Heat conduction, Joule heating, thermoelectric and thermionic cooling are included as well as non ideal effects such as contact resistance, finite thermal resistance of the substrate and the heat sink, and heat generation in the wire bonds. Various substrate materials (InP, Si, Cu, diamond) and thicknesses are studied as well as the effect of current spreading in different sample geometries. Comparisons to experimental results with InGaAsP-based thermionic coolers are made. Simulations demonstrate that single stage thin film coolers can provide up to 20-30 degrees centigrade cooling with cooling power densities of several 1000's W/cm/sup 2/.