Integrated microthermoelectric coolers with rapid response time and high device reliability

Microthermoelectric modules are of potential use in fields such as energy harvesting, thermal management, thermal imaging and high-spatial-resolution temperature sensing. In particular, microthermoelectric coolers (mu-TECs)-in which the application of an electric current cools the device-can be used to manage heat locally in microelectronic circuits. However, a cost-effective mu-TEC device that is compatible with the modern semiconductor fabrication industry has not yet been developed. Furthermore, the device performance of mu-TECs in terms of transient responses, cycling reliability and cooling stability has not been adequately assessed. Here we report the fabrication of mu-TECs that offer a rapid response time of 1 ms, reliability of up to 10 million cycles and a cooling stability of more than 1 month at constant electric current. The high cooling reliability and stability of our mu-TEC module can be attributed to a design of free-standing top contacts between the thermoelectric legs and metallic bridges, which reduces the thermomechanical stress in the devices.