A nanoscale thermoelectric device, which may be operated as a refrigerator or as a thermoelectric generator includes N-type and p-type active areas connected to a central terminal and end electrodes made of interconnect metal. Reducing lateral dimensions of the active areas reduces vertical thermal conduction, thus improving the efficiency of the thermoelectric device. The thermoelectric device may be integrated into the fabrication process sequence of an IC without adding process cost or complexity. Operated as a refrigerator, the central terminal may be configured to cool a selected component in the IC, such as a transistor. Operated as a thermoelectric generator with a heat source applied to the central terminal, the end terminals may provide power to a circuit in the IC.