Micro thermoelectric cooler fabrication: growth and characterization of patterned Sb2Te3 and Bi2Te3 films

A column-type micro thermoelectric cooler is being fabricated using p-type Sb₂Te₃ and n-type Bi₂Te₃ films (approximately 4 μm thick). The films are grown by thermal co-evaporation and patterned on Cr/Au/Ti/Pt (hot) connectors, which are deposited onto a silicon dioxide coated wafer. The column height is limited by control of the Te deposition rate. Although a high substrate temperature during thermoelectric film deposition is desired, it has been limited by the degradation of the photoresist used for patterning. The measured Seebeck coefficient and electrical resistivity of the thermoelectric films are reported, and preliminary results show that excess tellurium increases the Seebeck coefficient.