使用氮氣中性粒子束電漿處理之大氣常壓電漿輔助化學氣相沉積製備高效能銦鎵鋅氧薄膜電晶體研究

Abstract

在未來的3D顯示器中的趨勢，低溫多晶矽薄膜和銦鎵鋅氧薄膜是最具有潛力的材料以達成高遷移率和良好的均勻度的薄膜電晶體。由於銦鎵鋅氧薄膜的製程較簡單、成本較低和均勻性較好，夏普和三星都選擇銦鎵鋅氧薄膜做為新一代的顯示器。非晶銦鎵鋅氧薄膜電晶體具備較好的場效遷移率(>10 cm2/V．s)，較大的開關電流比(>106)，較小的次臨界擺幅和較穩定的電性，目前已被廣泛研究，可製造透明且隢性的顯示器。 在這篇論文中，我們選擇使用大氣常壓電漿化學氣相沉積(AP-PECVD)來沉積銦鎵鋅氧主動層和中性粒子束系統後處理於銦鎵鋅主動層。因為大氣常壓電漿系統在常壓下運作，因此可以降低成本且可利用在大面積的製造上。中性粒子束系統和傳統電漿相比之下，能確實地隔絕電漿中對元件造成缺陷的UV-rays、Chatge Bulid-up，使元件電特性更提升。 最後，我們成功地製作出藉由中性束氧電漿處理主動層之高效能非晶銦鎵鋅氧薄膜電晶體。經由能量500W中性束氧電漿處理過的銦鎵鋅氧當主動層的薄膜電晶體效能明顯地提升，它擁有相當的電子遷移率33.32cm2/V·s，更小的次臨界擺幅 147.8 mV/decade，更高的開關電流比0.53×106且較大的開通電流 安培明顯地優於未經中性束氧電漿處理過的。

Low-temperature polycrystalline-silicon thin-film transistors (LTPS-TFTs) and indium-gallium-zinc-oxide TFTs (IGZO-TFTs) are potential candidates for future technology of 3D displays. Due to IGZO-TFT have simple process, low cost and good uniformity these advantage, Sharp and Samsung decide use IGZO-TFT to be new generation display. The a-IGZO TFTs have attracted attention that due to its better field-effect mobility (>10 cm2/V．s), larger Ion/Ioff ratio (>106), smaller subthreshold swing (SS) and better stability. Furthermore, the a-IGZO TFTs can be applied on flexible substrate. In this investigation, we selected to use atmospheric-pressure PECVD (AP-PECVD) to deposit IGZO active layer and post-treatment by Neutral Beam System(NBS). With AP-PECVD, we could deposit IGZO thin film with atmospheric-pressure, so it could lower our cost and offer to large area manufacturing. Neutral Beam System could isolate UV-rays radiation, charge build-up compared with conventional plasma that could promote the electric characteristic. Finally, We successfully fabricated high performance a-IGZO TFT by AP-PECVD and plasma treatment by NBS. By the result, It reveals the high field effect mobility and better subthreshold swing are obtain from 500W NB sample.