On-chip solid-state cooling for integrated circuits using thin-film microrefrigerators

An overview of recent advances in solid-state cooling utilizing thin-film silicon germanium-based microrefrigerators is given. Key parameters affecting micro cooler performance are described. A 3-/spl mu/m thick 200/spl times/ (3 nm Si/12 nm Si/sub 0.75/Ge/sub 0.25/) superlattice device can achieve maximum cooling of 4/spl deg/C at room temperature, maximum cooling power density of 600 W/cm/sup 2/ for 40-/spl mu/m diameter device and fast transient response on the order of tens of micro-seconds independent of the device size. Three-dimensional electrothermal simulations show that individual microrefrigerators could be used to remove hot spots in silicon chips with minimal increase in the overall power dissipation.