a-IGZO 薄膜電晶體的製作與特性分析

Abstract

在本篇論文中，我們成功利用射頻濺鍍的方式製造出a-IGZO薄膜電晶體。由於射頻濺鍍擁有製程溫度低、大面積均勻性佳的薄膜特性，使得此項技術成為製作a-IGZO通道層的主要方法。我們藉由調整a-IGZO薄膜沉積製程參數，包括氧氣流量和製程功率控制，進行製作a-IGZO通道層應用於薄膜電晶體的元件特性分析，以得到適切的製程參數。然後對利用適切的製程參數製作的a-IGZO薄膜電晶體進行後段熱退火，或增加一層高摻雜濃度的IGZO薄膜於源/汲極和a-IGZO 主動層之間，以了解其對於元件特性的影響。 此外，在適切的a-IGZO薄膜電晶體上利用變溫量測來探討於元件電性的穩定性。最後，我們也發現在不同製程參數下所製作a-IGZO通道層的薄膜電晶體擁有不同大小遲滯現象，因此對於遲滯現象而言，其a-IGZO通道層的製程參數有顯著的影響。

In this thesis, we have successfully fabricated a-IGZO TFTs by depositing the channel films with a radio frequency (RF) sputter. Because the RF sputters have merits of low manufacture temperature and good uniformity on a large scale, making this deposition technique highly suitable for fabrication of the a-IGZO devices. In this thesis, the impacts of the deposition conditions, such as oxygen flow and deposition power, on the properties of the a-IGZO films are carefully explored in order to find suitable manufacture parameters. And then, the a-IGZO TFTs fabricated with the suitable manufacture parameters were subjected to different post annealing treatments to study the effects of the treatments. Moreover, effects of an n+ layer inserted between S/D metal and a-IGZO channel are demonstrated to be useful for enhancing the device’s output performance. We’ve also investigated the temperature stability of the devices by measuring the device characteristics at different temperatures. Finally, the hysteresis properties of a-IGZO TFTs are addressed and verified that the deposition parameters of the a-IGZO channel layer have a significant impact on the hysteresis window.