隨著積體電路微小化，元件運作時所產生的熱量遽增。快速上昇的運作溫度對於元件的可靠度及效能將產生莫大的威脅。而薄膜型熱電冷凍元件具有高冷卻功率（~數百W㎝-2）、降溫的反應時間迅速（~μs）、性能穩定且能夠與半導體製程匹配等優點，因此薄膜型熱電冷凍元件遂成為積體電路散熱的解決方案之一。而熱電元件的效能跟熱電材料的熱電優值（ZT）息息相關，Bi2Te3化合物是目前室溫下最佳之熱電材料。因此本論文利用直流濺鍍法製備Bi2Te3層狀薄膜，將Bi/Te 雙層複合薄膜依序鍍在長有氧化層之矽基材上。並利用後續熱時效處理，藉由固態擴散反應生成Bi-Te 化合物薄膜。探討不同Bi/Te厚度比對於整體薄膜熱電性質的影響。而本研究所採用主要的基板製程溫度為室溫，以得到較佳之薄膜平整度與附著特性，便於日後電子元件的整合。並且為了提升其熱電性質，引入了Bi薄膜退火製程，探討退火溫度與退火時間對於整體熱電薄膜微結構和熱電性質的影響。實驗發現，室溫製程的複合熱電薄膜平整度較佳，但是由於缺陷多，造成熱電性質不佳。因此利用Bi單層薄膜退火製程，減少了Bi薄膜的缺陷，並且在200℃/2hr退火後，可使Bi薄膜的Seebeck值達到-78μV/K。而經由不同Bi/Te薄膜厚度比的複合熱電薄膜實驗結果推測，隨著Bi2Te3化合物的生成，阻礙了後續Bi和Te原子的擴散，使得殘留的Bi薄膜影響整體複合薄膜的熱電性質。

With continuous miniaturization of very large-scale integrated circuits (VLSI), devices generate substantial heat during operation. A rapid increase in operating temperature causes serious reliability concerns and impacts on devices performance. Thin-film thermoelectric cooling devices own the advantages of large cooling power density、fast response time、stability and compatibility with semiconductor process technology. Thus, it becomes one possible solution to VLSI heat dissipation problem. The performance of the thermoelectric device depends closely on the figure of merit of the material. Bi2Te3 compound is known the best thermoelectric material at room temperature presently. In this study, Bi2Te3 layered compound was prepared by DC sputter deposition method. The Bi/Te bilayer thin films were first deposited on SiO2 substrate in sequence, and transformed into Bi-Te compound by thermal treatment through solid state reaction. The effect of Bi/Te thickness ratio on the thermoelectric properties of the Bi-Te composite thin films was investigated. In order to obtain the better planarization and adhesion for thin film integration considerations, the substrate temperature is maintained at room temperature. A Bi thin film annealing process was introduced to improve the thermoelectric properties of Bi-Te composite thin film. The effect of thermal annealing conditions on the microstructure and the thermoelectric properties of Bi-Te composite thin film was also investigated. It is observed that Bi-Te composite thin film has good planarization and poor thermoelectric properties caused likely by imperfect crystalline microstructure when the substrate temperature during deposition is room temperature. Therefore, we introduced an post-annealing step to reduce defects in Bi thin film, which shows a Seebeck coefficient of -78μV/K after 200℃/2hr annealing. According to the results for Bi/Te composite films with different Bi/Te thickness ratio, we speculated that the formation of Bi2Te3 composite retarded further interdiffusion between Bi and Te. Therefore, the residual Bi thin film affected the thermoelectric characteristic of Bi/Te composite thin film.

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