軟性透明a-IGZO薄膜電晶體之前瞻研究

Abstract

本計劃預計以三年時間，開發高效能、高穿透率非晶氧化物半導體（amorphous oxide semiconductor）的薄膜電晶體。研究元件電極接面、通道區域/閘極絕緣層介面特性、 與元件結構對電晶體效能的影響，並進行一系列的可靠度分析。在本計劃初期，藉由低 溫濺鍍法製作非晶氧化物薄膜，利用濺鍍氣體分壓的調控及沉積溫度來改變薄膜特性， 研究薄膜成份、晶相對於載子濃度與電特性的影響，並分析沉積條件對於穿透率等相關 光特性的影響。根據初期研究的成果，開發非晶氧化物薄膜電晶體，並針對電極接面與 閘極絕緣層接面進行改質。在研究中，我們將利用氧組成的調控對上述區域進行改質處 理， 並輔以元件結構的設計、與源極（ Source ） 汲極（ Drain ） 的重新配置 （re-configuration）提升元件效能，並以四端點探針量測來驗證上述的結果。最後， 以本計畫開發的高效能元件來研究非晶氧化合物載子傳輸的機制，並對該高效能元件進 行可靠度分析。利用熱應力（thermal stress）、電偏壓應力（bias stress）、與光浸 潤（light soaking）來加速元件退化，研究元件的可靠度與退化的物理機制。尋找影 響非晶氧化合物元件退化的關鍵因素，以期提升元件長時間的穩定性。

In this proposal, the author will develop a high-efficiency, high-transparency amorphous oxide semiconductor thin-film transistors (TFTs) within 3 years. The proposal will focus on improving performance by modifying TFT electrode junctions, interface properties between channel region/gate-insulators, and device configurations. At the end of this proposal, the reliability analysis will also be investigated and verified. In the first year, by using low-temperature sputtering system, deposition conditions such as sputtering gas-pressure and deposition temperature, will be used to change amorphous oxide thin-film properties. The changes in thin film carrier concentration and electrical characteristics will also be verified by analyzing thin-film composition and crystallization. The effects of deposition conditions on thin-film optical properties will also be studied. Consequently, in the second year, the author will develop amorphous oxide semiconductor thin-film transistors and focus on studies of TFT electrode and interface modifications. In the proposed studies, we will try to improve TFT performance by adjusting oxygen composition of electrode junctions and interface properties between channel region/gate-insulators. Additionally, we will design novel TFT structures and re-configure source and drain electrodes to improve TFT performance. All the improvements will also be verified by using the 4-probed measurement method. In third year, based on the developed amorphous oxide semiconductor TFT, the author will try to study the transport mechanism and its related reliability issues. By using thermal stress, bias stress, and light-soaking, the degradation of amorphous oxide TFTs will be accelerated. In this way, TFT reliability and degradation mechanisms can be investigated, and key issues on TFT’s decreased performance will be found. Hence, the TFT long-term stability should be also investigated.