在本論文中，我們探討了AlxGa1-xN/GaN異質結構材料下中的二維電子氣在量子井中的傳輸行為。我們一共對六塊AlxGa1-xN/GaN半導體樣品進行實驗與分析，其中三塊是未摻雜的AlxGa1-xN/GaN，x值為0.17、0.29、0.33，另外三塊則是鐵摻雜的AlxGa1-xN/GaN，x值各別為0.18、0.19、0.21，由此兩組樣品的實驗結果進行比較，觀察鐵摻雜對我們樣品的影響。
由霍爾實驗的結果，鐵摻雜的樣品載子濃度要比未摻雜的樣品來的低，而在溫度4.2K的載子遷移率，鐵摻雜的樣品要比未摻雜的高出將近一倍。同時，我們亦進行了低溫高磁場下SdH (Shubnikov-de Hass)效應的量測。在x=0.29與0.33之樣品發現電子占據了最低的兩個次能帶，且於x=0.29的樣品得到兩個能帶的能量差為109meV。我們也在樣品上觀察到明顯的電子自旋分裂使得SdH振盪出現拍頻效應的現象，而本次實驗中最大的自旋分裂能量差為 5.96meV，出現於x=0.21的樣品上。此外，經由照光實驗得知鐵摻雜的樣品皆能產生顯著的PPC effect，載子濃度至少上升23%，而未摻雜的樣品最多只提升了10.3%。

We discussed the electronic properties in AlxGa1-xN/GaN heterostructures. There are six different samples of AlxGa1-xN/GaN we prepared for this experiment, three of them are undoped AlxGa1-xN/GaN with different x values which is 0.17, 0.29 and 0.33, respectively. The others are Fe-doped AlxGa1-xN/GaN which the x value is 0.18, 0.19 and 0.21 for each sample. Comparing these two types’ materials’ results, we tried to confirm the impurity’s characteristic in our samples.
From the Hall measurement results, carrier concentration of Fe-doped AlxGa1-xN/GaN were pretty lower than undoped AlxGa1-xN/GaN, and the mobility at 4.2 K are almost two times to undoped AlxGa1-xN/GaN. At the same time, we performed Shubnikov-de Hass measurement, and two subbands of the 2DEG were populated on the samples for x value is 0.29 and 0.33. The energy separation for first two subbands is 109meV. We also observed obvious beat pattern in the SdH oscillations due to the spin splitting on the samples and the greatest spin-splitting energy is 5.96meV in our measurement. Furthermore, we observed evident PPC effect on the samples of Fe-doped AlxGa1-xN/GaN, the carrier concentrations increased at least 23% after illumination. Meanwhile the samples of undoped AlxGa1-xN/GaN can just produce 10.7% increment at most.

第一章 簡介 1
1-1前言 1
1-2 半導體異質結構 3
1-3 電子自旋 5


第二章 原理 7
2-1 Shubnikov-de Haas Effect 7
2-2 Hall Effect 9
2-3 PPC Effect 11


第三章 實驗介紹 12
3-1 樣品備製 12
3-2 變溫霍爾實驗 14
3-2.1 儀器介紹......................................14
3-2.2 實驗步驟......................................15
3-3 低溫實驗 21
3-3.1 Shubnikov-de Haas 實驗設定....................22
3-3.2 Quantum Hall Effect 實驗設定..................25
3-3.3 Conventional Hall Effect 實驗設定.............27
3-3.4 飽和電流與漏電量測接線........................29
3-4 Fast Fourier Transform 31


第四章 實驗結果與討論 35
4-1 樣品結構 ...35
4-2 變溫霍爾數據 ...37
4-2.1 Samples of undoped AlGaN/GaN..................37
4-2.2 Samples of Fe-doped AlGaN/GaN.................41
4-3 Shubnikov-de Hass 實驗結果 ...45
4-3.1 樣品KTH471...................................45
4-3.2 樣品KTH472...................................48
4-3.3 樣品KTH473...................................51
4-3.4 樣品KTH534...................................53
4-3.5 樣品KTH538...................................56
4-3.6 樣品KTH539...................................59
4-4 能帶分析 ...61

第五章 結論.................................... 63


References......................................68

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