低溫液態製程金屬氧化物薄膜電晶體

Abstract

溶液製程的金屬氧化物薄膜電晶體(IGZO,IZO,ZnO等)是最近研究的重點，尤於其能隙大穿透率高，並且有高的載子遷移率，製程成本是非常低廉等優點。然而，其過高的製程敏感性和元件操作穩定性及需要在高溫中退火限制了其在徹底商業化，近年來研究顯示透過調高In(銦)比例，可讓金屬氧化物於低溫製成時，擁有高的環境穩定性，以及透過DUV退火能大大降低製程溫度。 本論文從一開始如何做出一個金屬氧化物電晶體開始講起，並且為了要改善元件的電性，嘗試了不同的金屬氧化物(IGZO , IZO , ZnO)，且改變不同金屬前驅物混合的比例，以及不同Zn前趨物，以求達到一個極佳化的電性。為了能使整個製程控制在較低的溫度，我們也對上述不同的金屬氧化物進行使用DUV機照射並使用不同的後退火溫度測試並製成了薄膜電晶體並進行電性比較，發現還是IGZO薄膜電晶體在DUV環境下擁有較好的效應並得到較好的電性。 我們使用IGZO，並應用DUV(254nm)照射兩小時，加上300˚C 後退火得到最佳的遷移率～1 cm2V-1s-1，遠高於只有300˚C退火的遷移率 ～0.2 cm2V-1s-1，得到UV退火能有效改善電性。

Solution-processed indium-gallium-zinc-oxide TFTs had been studied for recent years. The most attractive is the low cost fabrication processes, high charge carrier mobility and high optical transparency. However, the performance on solution processed metal-oxide TFTs is not stable, it need high annealing temperature (>400℃) to achieve high performance device characteristics. Recently, some research show that we can decrease the annealing temperature to obtain high performance solution processed metal-oxide TFTs with high ratio In IGZO. And we can also increase excellent environmental stability and high mobility with DUV annealing. In this study, we fabricated the conventional thin-film transistor with different composition metal-oxide semiconductors such as ZnO, IZO, and IGZO and different Zn precursor to achieve high mobility. In order to decrease annealing temperature , we try to use DUV annealing and post-thermal annealing .We found that IGZO have high performance with DUV annealing and post-thermal annealing. The IGZO TFT with UV annealing and post-thermal annealing (300˚C) have mobility ～1 cm2V-1s-1 , but IGZO TFTwith thermal annealing (300˚C) have mobility ～0.2 cm2V-1s-1.