大氣壓電漿輔助化學氣相沉積系統之氫電漿處理氧化銦鎵鋅薄膜電晶體與偏壓變溫不穩定特性研究

Abstract

因為非晶的氧化銦鎵鋅薄膜電晶體，具備較好的場效遷移率(>10 cm2/V．S)，較大的電流比值(>106)和較穩定的電性，目前已被廣泛研究, 並且應用在下世代的主動式陣列顯示器，例如: 液晶顯示器和平板顯示器。 在這篇論文中，我們使用大氣壓電漿輔助化學氣相沉積系統之氫電漿來沉積我們氧化銦鎵鋅通道，這系統不用在真空系統下運作，因此可以降低我們的成本，並且可以大範圍面積的製作。 最近，大部分薄膜電晶體的耐受性與可靠度問題都與偏壓變溫不穩定性有關，也就是說，偏壓變溫不穩定性經常用來討論薄膜電晶體衰退機制，並在可靠度的議題上扮演重要的角色。 在這篇研究裡，透過變化閘極偏壓應力條件，來研究氧化銦鎵鋅電晶體的不穩定性。我們討論的可靠度議題像是正偏壓應力，正偏壓變溫不穩定性，負偏壓應力，和負偏壓變溫不穩定性等研究。

Amorphous InGaZnO (a-IGZO) Thin Film Transistors (TFTs) has been studied extensively for their perspective applications in next generation active-matrix displays such as liquid crystal displays and flat-panel displays, due to its better field-effect mobility (>10 cm2/V．S), larger Ion/Ioff ratio (>106), and better stability electrical . In this letter, we used in-situ Hydrogen plasma for atmospheric-pressure PECVD to deposit our IGZO channel. We could deposit IGZO thin film without vacuum system, therefore, it could reduce our cost, and applied to large area manufacturing. In recent, most practical problems in the endurance and reliability of all thin-film transistors are nearly interrelated to Bias Temperature Instability (BTI). That is to say, BTI plays a crucial role in the reliability issue and has become one of the most frequently discussed degradation mechanisms in thin-film transistors. In this study, various gate-bias-stress conditions are applied to study the instability of a-IGZO TFTs. We discussed reliability issues such as positive bias stress (PBS), positive bias temperature instability (PBTI), negative bias stress (NBS) and negative bias temperature instability (NBTI) in IGZO thin-film transistors.