以化學性氧化層加化學氣相沈積氮化處理所成長之極薄閘極氮氧化層特性之研究

Abstract

摘 要 在未來極大型積體電路的應用中，成長極薄氧化層已是不可避免的趨 勢。不過，當我們要將氧化層長到如2nm薄的厚度時，這層膜要要穩定中成長和長得好實在不是件容易的事。就算我們真的能長出這麼薄的氧化層來，因為這個厚度在是太薄而且硼原子實在是太活潑了，硼原子還是可以輕易穿過這層氧化層造成了可靠度的問題。為了克服這個可靠度的問題，我們得用新的方法來長出較好的閘極氧化層。首先，在我們要用乾氧來長閘極氧化層之前，我們先長一層化學性的氧化層。接著，我們用純的氨氣來做氮化的處理。最後我們在放到乾氧裡長就完成了這個新的閘極氧化層的製造。而這個化學性的氧化層和那個能夠在氧化層頂端以及矽氧化層介面間堆積的氮原子可改進I-V, C-V的特性。在本論文的研究中，也會告訴大家為什麼我們可以降低漏電流和抵擋硼穿透。是以，元件在越做越小後，我們的這個極薄閘極氮氧化層還是有實用性而應用在高介電材料上也是見可令人預期的事。

Abstract It is an inevitable trend for the gate dielectric to fabricate the ultrathin oxide in the future ULSI applications. However, it is difficult to fabricate the ultrathin gate oxide about 2nm in a stable and good environment. In spite of success of it, the boron atoms will penetrate into the thin oxide easily and lead to the reliability problem because the thickness of the oxide is too thin and boron is one kind of active atoms. In order to overcome its reliability problem, we use a new method to fabricate a better gate oxide. First, we grow a chemical oxide before the dry oxidation is put into practice. Second, it will be nitridized in the pure ammonia gas. Finally, the ultra-thin gate oxynitride is finished after the dry oxidation is carried out. The chemical oxide and the nitrogen that piles up at the top of the oxide bulk and at the interface between the silicon and the gate oxide will improve the I-V characteristic and C-V characteristic. We will know that the leakage current will be lower and the boron penetration will be suppressed in out studies. Therefore, it is practicable for our ultra-thin oxynitride if the device is scaled down. In the meanwhile, it can also be predicted that it can be applied to the high-K materials.