Fabrication and Evaluation of a Thermoelectric Microdevice on a Free-Standing Substrate

Using shadow masks prepared by standard microfabrication processes, we fabricated in-plane thermoelectric microdevices (4 mm x 4 mm) made of bismuth telluride thin films, and evaluated their performance. We used Bi0.4Te3.0Sb1.6 as the p-type semiconductor and Bi2.0Te2.7Se0.3 as the n-type semiconductor. We deposited p- and n-type thermoelectric thin films on a free-standing thin film of Si3N4 (4 mm x 4 mm x 4 mu m) on a Si wafer, and measured the output voltages of the microdevices while heating at the bottom of the Si substrate. The maximum output voltage of the thermoelectric device was 48 mV at 373 K.