室溫加水液相沉積氧化矽之研究

Abstract

液相沉積是一種在水性溶液中成長氧化矽膜的方法,整個製程溫度為室溫, 設備的價格不貴,可免去傳統長膜方法所遭遇的一些問題,在未來超大型積 體電路技術的發展上頗具有前景.在本研究中,我們發展出一種新的液相沉 積方法,不需要使用硼酸或鋁粉,只藉著加入純水,便可以在含有過飽和氧 化矽的氫矽氟酸溶液中將氧化矽沉積於矽基板上.液相沉積膜的成長速率 受控於加入水量的多寡以及成長溫度,若能在長膜的基板上先有一層自然 氧化膜的保護,長膜的沉積速率控製在每小時83nm以下,再經過500 'C氧氣 熱處理一個小時,這樣的液相沉積膜會有比較小的漏電流,比較高的崩潰電 場分佈,以及較低的界面缺陷密度.這種液相沉積膜的導電機制與熱氧化膜 中所發現的很類似,主要是由Fowler-Nordheim穿透型導電所控制. Liquid phase deposition (LPD) is a method of growing silicone in aqueous solution. Resulting from the room-temperatureess and inexpensive equipment, the LPD method can avoid thelems from the conventional techniques. It will be a veryising technique in the development of VLSI techanology. In thisarch, a novel LPD method has been developed. The silicon oxidecan be deposited on the Si-substrate in silica supersaturatedofluosilic acid (H2SiF6) solution by using H2O instead of H3BO3l. The silica deposition rate can be controlled by the amount ofadded. The deposited film is found to be amorphous and porous incture, and slightly silicon-rich in composition. The filmited on the substrate surface passivated with native oxide atposition rate below 83 nm/hr, and annealed at 500 'C in oxygenent for 1 hour exhibits excellent low leakage current, highkdown electric field distribution and low interface-trap density.conduction mechanism of LPD-oxide is similar to that of thermale, it is dominated by Fowler-Nordheim tunneling conduction attemperature.