金屬氧化物半導體是一種高透明度的電子材料，具有高遷移率的優勢，在顯示器的應用上，金屬氧化物薄膜電晶體 (Metal Oxide Thin Film Transistor，MO-TFT) 的元件結構與製程設計與目前主流的非晶矽薄膜電晶體非常接近，因此引起了面板製造商的高度關注，其中又以氧化銦鎵鋅 (InGaZnO，IGZO) 材料開發最為廣泛。 本研究首先針對作為主動層的IGZO薄膜和作為閘極絕緣層及鈍化層的SiOx薄膜做基本特性引出，匹配組成一蝕刻終止層 (ESL) 結構的薄膜電晶體，得到了載子遷移率為15.8 cm2 / V·s、電流開關比大於107的元件，並且展開成為陣列驅動背板，成功點亮一5.5吋液晶顯示器；接著我們關注於氧化物電晶體承受高電壓的可能性，由於短通道元件操作在高電場的環境下，帶來的焦耳熱、熱載子、游離碰撞等效應，導致元件發生電流崩潰，而我們藉由IGZO薄膜沉積時的氧流量調整，降低半導體中的載子含量，減少熱載子效應影響，使電晶體操作在65 V的閘極電壓和56 V的汲極電壓下沒有發生元件崩潰的現象。 根據此研究結果，我們確認了MO-TFT體操作在高電場下的可行性，除了在顯示器上的應用，未來也可以作為高功率元件開發的參考。;Metal oxide semiconductor is a highly transparent electronic material, it has high carrier mobility and can be easily replaced by the amorphous silicon backplate technology. As we know, the most widely researched and developed is the indium gallium zinc oxide (InGaZnO，IGZO). In first, we analyze the basic thin film characteristics of IGZO and SiOx, that is two important key of metal oxide thin film transistor (MO-TFT), and formed a MO-TFT with an etching stop structure which has carrier mobility of 15.8 cm2 / V·s and the current switching ratio over 107. We also successfully demonstrated an array backplane to driven a 5.5-inch liquid crystal display. Then we focus on the high voltage device develop, because the MO-TFT operating under the high current and high electric field environment, such induced the joule heating near the drain side, simultaneously, the short channel brings the hot carrier effect, therefore, serious impact ionization occurs in the channel and lead to the TFT breakdown. In order to improve the TFT breakdown caused by short channel elements under high voltage, we adjusted the oxygen flow during the deposition of InGaZnO thin film to reduce the carrier content in the active layer and inhibition the effect of the hot carrier. Finally, the MO-TFT with 8 μm channel length which operates at a gate voltage of 65 V and a drain voltage of 56 V can be without breakdown behavior. Based on the results of this study, we confirm that the short channel MO-TFT can operate in a high electric field environment, not only as a display application, but also as a reference for the development of high-power device.
