Year: 2006
Type: article
Abstract: We fabricated a silicon microrefrigerator on a 500-$mu$m-thick substrate with the standard integrated circuit (IC) fabrication process. The cooler achieves a maximum cooling of 1$^circ$C below ambient at room temperature. Simulations show that the cooling power density for a$hbox40times hbox40 muhboxm^2$device exceeds 500$hboxW/cm^2$. The unique three-dimensional (3-D) geometry, current and heat spreading, different from conventional one-dimensional (1-D) thermoelectric device, contribute to this large cooling power density. A 3-D finite element electrothermal model is used to analyze non-ideal factors inside the device and predict its limits. The simulation results show that in the ideal situation, with low contact resistance, bulk silicon with 3-D geometry could cool$sim hbox20 , ^circhboxC$with a cooling power density of 1000$hboxW/cm^2$despite the low thermoelectric figure-of-merit (ZT) of the material. The large cooling power density is due to the geometry dependent heat and current spreading in the device. The non-uniformity of current and Joule heating inside the substrate also contributes to the maximum cooling of silicon microrefrigerator, exceeding 30% limit given in one–dimensional thermoelectric theory$DeltaT_max=hbox0.5hboxZT_c^2$, where$T_c$is the cold side temperature. These devices can be used to remove hot spots on a chip.
Authors: Y. Zhang, G. Zeng, A. Shakouri
Institution: University of California, Santa Cruz
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2294587811