研究與提升保護層對於氧化鋅薄膜電晶體之影響

Abstract

在本篇論文當中，我們利用電漿輔助化學氣相沉積系統與原子層化學氣相沉積系統，在氧化鋅薄膜電晶體上面沉積氧化矽、氧化氮和氧化鋁的保護層。但是沉積保護層後所有的元件都有著載子濃度太高而喪失電晶體開關特性的問題。針對此問題，我們利用常壓的氧氣退火、改變沉積氧化鋅過程中的氧氣流量、以及電漿處理等方式，調整通道中自由載子的數目。在元件的通道經過一氧化二氮的電漿處理之後，我們可以有效的改良電晶體的切換特性。我們也利用X光電子能譜儀去研究經過一氧化二氮電漿處理後氧化鋅表面化學鍵結的情況。

In this thesis, we fabricated ZnO TFTs with various passivation layers deposited by PECVD or ALD. Four splits of passivation layers, namely, silane-oxide, silane-nitride, TEOS-oxide, and aluminium oxide are employed and the device characteristics are explored in this work. Nevertheless, all of the devices are highly leaky after passivation and lose their switching capability. To address this issue, we study the effects of various measures, including thermal annealing conducted in oxygen ambient, varying the oxygen flow during the channel deposition, and plasma treatments performed on the active layer, on the performance of passivated devices. Among these approaches, the use of a N2O plasma treatment is found to be most effectively in recovering the switching characteristics of the passivated devices.