Enhanced Hot Spot Cooling Using Bonded Superlattice Microcoolers With a Trench Structure

In this paper, we describe how to use Si/SiGe superlattice microcoolers to cool the target hot spots and how a trench structure could enhance its cooling performance. The microcooler chip is gold fusion bonded with a 65 mum-thick silicon chip, where heaters are fabricated on the opposite of fusion bonding layer to simulate the hot spots. Our 3-D electrothermal simulations showed that with a trench structure, the maximum cooling and cooling power density could be doubled at hot spot region. Our experimental prototype also demonstrated a maximum cooling of ~ 2degC reduction at hot spot or a maximum cooling power density of 110 W/cm with trench structure as compared with the 0.8degC cooling without trench structure. This two-chip bonded configuration will allow the integration of spot coolers and ICs without impact on microelectronics processing process. It could be a potential on-chip hot spot cooling solution.