Preparation of Bismuth Telluride Compound Semiconductors through Thin Film Reactions

Thermal management of integrated circuits (IC) chips has become a critical issue because of poor heat dissipation induced performance degradation and reliability concerns. Lately, thin-film type thermoelectric micro-cooler is being considered as a potential solution to the chip cooling problem. Hence, high quality thin film thermoelectrics becomes essential in making such micro cooling devices. In this study the preparation and characterization of the bismuth telluride compound semiconductor in thin film forms were conducted. The Bi-Te thin films were prepared using sequential sputter deposition followed by thermally induced Bi/Te interfacial reactions. The best Bi-Te thermoelectric thin film obtained has the Seebeck coefficient of-202 μV/K, the resistivity of 2.3×10-3 Ω⋅cm, and the thermal conductivity of 0.71 W/m⋅K after the Bi/Te bilayer samples were annealed at 200 °C for 24 hours. The effects of process parameters and annealing conditions on thermoelectric properties of the Bi-Te composite thin films are also discussed