利用穿隧式電子顯微鏡的探針產生在鎳鋁合金(100)面上的局部氧化反應; STM tip-induced local oxidation on the NiAl(100) substrate

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/43853

Title:	利用穿隧式電子顯微鏡的探針產生在鎳鋁合金(100)面上的局部氧化反應;STM tip-induced local oxidation on the NiAl(100) substrate
Authors:	林巧雯;Chew-Wen Lin
Contributors:	物理研究所
Keywords:	氧化鋁;氧化反應;蝕刻;穿隧式電子顯微鏡;STM;oxidation;lithography;alumina
Date:	2010-07-12
Issue Date:	2010-12-08 14:23:20 (UTC+8)
Publisher:	國立中央大學
Abstract:	利用穿隧式電子顯微鏡(scanning tunneling microscopy, STM)在低曝氧量的鎳鋁合晶表面上進行蝕刻的實驗。首先發現氧化條紋的產生會以兩種不同的模式出現。其一是在低功率(降低偏壓)條件下，氧化條紋會出現在部分的掃描範圍內，但是出現的位置是我們無法預測的。另一種是在高功率(增高穿隧電流)條件下，氧化條紋生成的位置可以被移動的探針來控制。接著實驗利用高功率條件控制氧化條紋生成，發現條紋生成的寬度、高度特性會隨著增加外加偏壓、穿隧電流和樣品溫度而增長，不過當探針與表面間的距離超過某一限定的高度後，條紋的寬度會變窄，甚至沒有條紋生成。另外不同種的反應物也會影響氧化條紋的生成特性。在此實驗顯示曝水氣(H2O)會比曝氧氣(O2)能產生更寬且更高的氧化條紋。此外，在我們的實驗中發現最精細的氧化條紋寬度為3 nm。 Nano – strips formation produced on pre-oxidation surface and a NiAl (100) substrate, caused by STM tip under constant current feedback in ultrathin vacuum (UHV) conditions is reported. Firstly, we lower the tip toward the surface by either decreasing the bias or increasing the tunneling current. The former uses a lower power and the Al2O3 pattern is formed through a self-organized manner, exhibiting an Al2O3 strip of width as small as 3 nm, but locations of the strips can’t be predicted. The later uses a higher power; although broader Al2O3 strips (about 8 nm wide), the patterns can be controlled by the tip motion. Then we use the higher power approach to discuss the mechanism that is clarified through evolution of the grown Al2O3 strip with the bias voltage, tunneling current, temperature (100 K and 300 K) and reactants (oxygen / water). Generally, the width increases little with the bias. The width always increases with the tunneling current. At a higher temperature (~300 K), the strip can be grown with a power (I x V) smaller than that at a lower temperature (~100 K). The strips can also be grown in a water-rich environment (humidity 80 %) with a power smaller than that in an oxygen-rich environment.
Appears in Collections:	[Graduate Institute of Physics] Electronic Thesis & Dissertation

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