在本文中,首先我們要討論的是p型氮化鎵歐姆接觸之研究。由於氮化鎵是一種寬能隙半導體材料，且在p型的雜質摻雜方面仍然無法有效地突破瓶頸，因而造成在製作p 型氮化鎵電洞濃度低和半導體電阻大且在自然界中找不到一個金屬的功函數(work function)大於p型氮化鎵的功函數（~6.5eV），所以在製作p 型氮化鎵的歐姆接觸仍然是一項難題。

　　在我們實驗中使用的試片，經霍爾測量其電洞濃度值為7×1017 cm-3。由於在一些文献中記載了以金（Au）基礎的金半接面會有熱穏定性的問題，而釕(Ru)則相對的有良好之熱穏定性。所以，我們使用四種高功函數的金屬配合釕(Ru)形成,Ir/Ru、Ni/Ru、Pt/Ru 和Pd/Ru 之電極結構且在氧氣中回火，試圖降低蕭基能障、以達成p 型氮化鎵的良好歐姆接觸，其最佳接觸電阻分別為1.87×10-3Ωcm、3.01×10-2Ωcm2、5.42×10-3Ωcm2、7.54×10-4Ωcm2。另外我們也以Ni/Au 為電極且在500℃ 氮氣中回火、得2.21×10-2Ωcm2。與Ni/Au比較的話，除了Ni/Ru的結果比較差外,其他三種的結果都是較好的。其中又以Pd/Ru在氧氣中經500℃回火後的結果最為特出。所以,我們對其進行微結構之分析，根據資料分析後的結果指出，Pd 在介面中扮演一個可以防止氮擴散至表面的阻擋層。這大大降低了氮缺陷在半導體表面的數量，避免了我們活化度本來就不高的Mg受體進一步被補償掉。

　　接下來是本文中另一研究項目,就是氮化鎵光檢測器之製作。本論文係使用MOCVD生長之未摻雜之氮化鎵為基板，製作金屬-半導體-金屬光偵測器。文中討論以不同金屬電極對偵測器的電壓電流曲線之影響， 其中為了得到更高的蕭基能障我們特地選用了濃度為5.72×1016 cm-3的未摻雜氮化鎵基板。而我們的指叉狀光罩,指和指縫之寬同為10µm，金屬則使用Ir/Au、Ru/Au、Ni/Au、Au、Ru等 。實驗結果得知，金屬電極元件之光暗電流比和光響應度皆以Ru/Au 最好,而其光暗電流比和光響應度分別是9.72×103和 1.99×10-1 A/W。接下來,我們將其放入充滿氧氧的高溫爐中,回火二十分鐘後取出。我們發現回火確實可以降底元件的暗電流,但是也使到光電流降低。雖然,它們的光暗電流比整體上是上升的。經氧回火後.Ru/Au的光暗電流比和光響應度分別為9.48×105和 2.45×10-2 A/W。在一個給定的頻寬500Hz 下，我們可以算出Ru/Au金半金光檢測器相關的雜訊功率密度、歸一化的檢測度為2.31×10-13 W 、1.94×1012 cmHz0.5W-1。

　　在透明材料當中，我們可以發現在回火前氧化鋅摻鋁會因為暗電流太大而完全無法量測到光電流。吾人又以在氮氣中回火的方式意圖降低暗電流,結果金屬電極之暗電流確實是都降低了,光電流也隨之而來了。經過500OC的光光檢測器有最好的光暗電流比高達3.28×105,其光響應度為0.26A/W。在一個給定的頻寬500Hz 下，我們可以算出氧化鋅摻鋁金半金光檢測器相關的雜訊功率密度、歸一化的檢測度為4.13×10-14 W 、1.08×1013 cmHz0.5W-1。

　In this thesis, First we must discuss are research the ohmic contact of P-type GaN. Because the GaN is one kind of larger bandgap semiconductor material, Also still was unable in the p-type impurity doping aspect effectively to break through the bottleneck, Thus creates in manufactures the p-type electricity hole density low and the semiconductor resistance is larger .Furthermore, we can't find a metal in the nature the work function (work function) to be bigger than the work function of p-type GaN (~6.5eV),Therefore was manufacturing the ohmic contact of p-type GaN still was a difficult problem. Tests previewing in us which uses, its electricity hole density value after Hall measurement for 7×1017cm-3. Because recorded in some papers ,Au based contact could have the heat stable question by the gold(Au), but ruthenium (Ru) then relative has the good heat stable. Therefore, We use four kind of high work functions metal coordination ruthenium (Ru) to form,Ir/Ru, Ni/Ru, Pt/Ru and Pd/Ru electrode of structure also annealing in oxygen ambient .Attempts to reduce the Schottky barrier height, achieves the good specific contact resistivity .Its best specific contact resistivity respectively be 1.87×10-3Ωcm2,3.01×10-2Ωcm2, 5.42×10-3Ωcm2, 7.54×10-4Ωcm2.Moreover we also by Ni/Au is the electrode also annealing with nitrogen in 500℃, its specific contact resistivity is 2.21×10-2Ω cm2. With Ni/Au comparison, other three kinds of results all are better except Ni/Ru. Pd/Ru is the best result in the oxygen after annealing with oxygen in 500℃ .Therefore, we carry on analysis the microstructure to it. After the material analysis result pointed out, Pd in lies between in the surface to act a diffusion barrier to be forbid the outdiffusion of nitrogen. This greatly reduced the nitrogen flaw in the semiconductor surface quantity, avoided our activating the originally not high Mg acceptor further to compensate.

　And then another research project in the article, we have successfully fabricated the interdigital metal-semiconductor-metal (MSM) photodetectors on undoped-GaN substrate. In the article discusses by the different metal electrode to influence the detecting voltage current curve. In order to obtain higher barrier height , we especially to select the density undoped-GaN substrate for 5.72×1016 cm-3. In this work, the finger width is 10µm and the spacing also is 10µm.The metal uses Ir/Au, Ru/Au, Ni/Au, Au and Ru. The experimental result shows the dark current compares with photocurrent (current contrast ratio) by Ru/Au is the best result. Under the UV condition of light exposed and 5V bias voltage, its current contrast ratio and the responsivity is 9.72×103 and 1.99×10-1 A/W, respectively. Furthermore, we sent sample into the high temperature furnace in oxygen ambient, and after annealing 20 minutes takes out. We discovered the annealing truly may lower the dark current, but also causes to the photocurrent to reduce. Although, their current contrast ratio is rise in the whole. After oxygen annealing Ru/Au current contrast ratio and responsivity is 9.48×105 and 2.45×10-2 A/W, respectively. For a given bandwidth of 500Hz, the corresponding noise equivalent power (NEP) and the normalized detectivity D* for MSM photodetector are calculated to be 2.31×10-13 W,1.94×1012 cmHz0.5W-1. In the transparent material, the transmittance of Sputtering-AZO films for thickness of 1000Å was 92.61% at wavelength of 400 nm. We may discover the zinc oxide doped aluminum to be able too greatly before annealing .Thus, completely to be unable detect photocurrent because of the dark current too big. Furthermore, we used the annealing method to reduce the dark current in the nitrogen ambient. Finally the dark current truly was all reduced photocurrent current also following. The best photo/dark current contrast ratio was discovered after annealing 500OC . Under the UV condition of light exposed and 3V bias voltage, it’s to reach as high as 3.28×105, responsivity is 0.26A/W. For a given bandwidth of 500Hz, the corresponding noise equivalent power (NEP) and the normalized detectivity D* for MSM photodetector are calculated to be 4.13×10-14 W, 1.08×1013 cmHz0.5W-1.

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