A micro-integrated Peltier heat pump for localized on-chip temperature control

Abstract

A thin-film Peltier heat pump was fabricated using standard semiconductor patterning and etching techniques. The device consisted of chrome–gold and bismuth telluride metallization to form the thermoelectric junctions. The device achieved a maximum heat-pumping rate of −24 μW at a current of 0.89 mA when operating in the cooling mode. These values were less than expected primarily due to excessive contact resistance at the Au–Bi2Te3 junctions of the Peltier device. Thermal isolation of the Peltier device on a 2.4 μm thick oxide bridge was used to enhance device performance. Complete etching of the silicon surrounding this oxide bridge was not possible, due to resultant damage of the bismuth telluride thin film. The silicon remaining increased thermal losses, resulting in the Peltier device lowering the temperature of the oxide bridge only 0.23 °C below ambient.