本論文主要探討濕氧化條件對AlAs/GaA界面的穩定性以及電性傳導的影響，利用改變氧化時間和爐內退火（in-situ anneal）觀察表面形態及拉曼光譜的變化，推論氧化機制以及造成剝離（delemination）的原因。利用電流電壓（I-V）、電容電壓（C-V）量測來分析其介面能態，以及計算AlAs濕氧化後氧化層之介電係數。
本論文首先磊晶成長不同厚度的AlAs結構在420℃至460℃之間進行濕氧化實驗，隨著厚度的增加AlAs的氧化速率增快，在460℃下，厚度100nm的速率約是30nm的8倍。接著對不同氧化時間的試片進行熱穩定試驗以及拉曼光譜分析，我們發現到試片的熱穩定與As及As2O3的移除有密切的關係。要獲得熱穩定性高的氧化AlAs層，可經由延長氧化時間或是爐內退火來移除高揮發性的氧化中間產物，避免剝離的發生。
在電性分析中，我們共利用三種不同氧化時間的元件進行C-V與I-V量測。由實驗結果發現氧化量極少的元件，其電容量測結果近乎一個常數，表示在AlAs/GaAs介面尚無缺陷存在。隨著氧化時間增加，在電容電壓圖中可以觀察其明顯的變化，顯示已有介面能態存在，但是由電流電壓圖中可以發現到未氧化完全的元件，在約0.8V就造成電流導通。當氧化時間延長至元件完全氧化，氧化層就可以有效地阻絕電流，並由電容分析發現AlAs/GaAs介面不只存在了介面能態所貢獻的缺陷電容，還發現了有固定電荷的存在。

In this thesis we study the influence to the thermal stabilities and conduction of oxidized AlAs/GaAs interface. The surface morphology and Raman spectra are obtained by varying the oxidation time and in-situ annealing to deduce the oxidation mechanism and the reason for delemination. The conduction and interface-state properties of oxidized AlAs are investigated by varying the oxidation time using current-voltage (I-V), capacitance voltage (C-V) measurements.
We first grew epitaxial structures with different AlAs thickness for oxidation experiment. Data are presented demonstrating that the lateral wet oxidation of AlAs layer is strongly influenced by its thicknesses. The oxidation length decreases rapidly with decreasing AlAs thickness. At 460℃ the oxidation length of 100-nm-thick AlAs layer is over 8 times longer than that of 30 nm thick AlAs layer. Then the thermal stability of the AlAs layer with different oxidation time is studied by Raman spectroscopy and Nomarski microscopy. We find that the thermal stability of the mesas depends strongly on the desorption of As and As2O3. Thermally stable oxide layers can be achieved when volatile intermediates in the oxides are removed by either elongating thermal oxidation or in situ annealing of partially oxidized AlAs layers.
We use three devices with different oxidation time to carry on C-V and I-V measurements. With short oxidation time, CV spectra show a constant capacitance without any frequency dispersion, implying defect free AlAs /GaAs interfaces. For longer oxidation, C-V spectra show frequency dependent characteristics, consistent with the presence of interface states between oxidized-AlAs/GaAs. However, I-V characteristic of incompletely oxidized devices shows that the oxidation layer is not enough to effectively block the current flow. Effective current blocking is achieved for increasing time to complete oxidation. Besides the interface states, we observe a presence of significant fixed charge for such oxidized devices.

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