In this paper we describe the experimental results of Si/SiGe superlattice microcoolers, which are used to cool the target hot spot on a 65μm-thick silicon substrate. The device areas under test range from 50×50 to 150×150 μm2. We measured the cooling temperature at the hot spot region versus the current supplied to the microcooler, as well as the thermal resistance, and the cooling power density (CPD, also defined as heat flux — the flow of heat per unit area in W/cm2) of these devices. The experimental results show the maximum cooling at the hot spot region approaches 1°C for device area 150×150μm2 at 80°C, and CPD up to ∼110W/cm2 for device area 50×50×2 μm2 (two 50×50μm2 device array, as illustrated in Figure 3) at 80°C. The two-chip bonded configuration will allow the integration of spot coolers and integrated circuit chips with minimum impact on the processing of microelectronic devices. Key parameters limiting the cooling performance at the hot spots are also discussed.
