在臭氧水中成長二氧化矽薄膜層之研究

Abstract

本論文可分為兩個部分：在第一部分中，我們利用臭氧水擁有高氧化力的特性，成長一層薄氧化層；藉著改變不同的濃度、溫度和浸泡時間，來研究這些因素對氧化層厚度的影響。臭氧水濃度的增加或溫度的升高都會使氧化層的厚度變厚，而且在剛最初的10秒內，氧化層幾乎已經達到飽和的厚度，之後的厚度增加非常緩慢。 在第二個部分中，我們在長閘極氧化層之前，不同於傳統的RCA方法，在最後一步浸泡HF之後再浸泡臭氧水；因此在長閘極氧化層之前就會先成長一層緻密的薄氧化層。我們利用做出MOS電容來量測電性，和傳統的製程方法比較。我們發現這種製程下的漏電流密度會變小、崩潰電壓會上升，也會有較少的捕捉電荷。浸泡臭氧水的濃度愈高、浸泡的時間愈長，元件的特性也會變得愈好。

There are two parts in the thesis. In the first part, we use the high oxidizing potential of ozonated DI-water to grow a thin chemical oxide layer. The factors including the concentration, temperature and immersion time were controlled to find the relation between these factors and the oxide thickness. Increasing the concentration, temperature will increase the thickness of oxide. The thickness almost reaches saturation within 10 seconds, and the oxide film was grown very slowly for the continuous immersion time. In the second part, we use a process different from the conventional RCA clean before gate oxide growth. An ozonated DI-water immersion process was added at the last HF dip step. A dense structure oxide was grown before thermal gate oxide growth. A MOS capacitor was manufactured to measure the electric characteristics. The leakage current density and trap charges will decrease and the breakdown voltage will increase when the sample immersed ozonated DI-water before growing thermal gate oxide. The higher concentration and the longer immersion time will have a better performance for the device.