Silicon Microthermoelectric Coolers for Local Heat Removal in Integrated Circuit Chips

Advancements in electronic device fabrication with increasing integration levels have resulted in very high device densities. This has led to higher power dissipation and heat fluxes, increasing integrated circuit (IC) operating temperature. High and nonuniform heat generation degrades device and system performance. Therefore, thermal management to keep ICs within prescribed temperature limits is an important challenge for reliable and economic performance. Cooling techniques, including liquid coolants and air conditioning (AC), have been utilized to remove heat at the package and system level. However, these techniques must overcome high thermal impedances and require complex integration, while global cooling is generally wasteful, inefficient, and expensive. To improve thermal management, we have developed Si microthermo-electric coolers (mu TECs) with areas as small similar to 10(-5) cm(2) that can be integrated on-chip near local hot spots using the standard fabrication processes. While Si mu TECs cannot achieve low base temperatures, they can actively pump relatively high heat fluxes directly to a heat sink, thus reducing local temperature increases and allowing targeted rather than global waste heat removal. We demonstrate mu TECs that can pump up to 43 W cm(-2) of locally generated excess heat with no increase in chip temperature.