在本論文中，我們利用有機金屬化學氣相沉積系統成長出Ⅲ-Ⅴ族p型氮化鎵材料。我們利用一些分析設備來對我們在不同溫度下所成長出來的p型氮化鎵磊晶品質上進行分析，而分析的設備包含霍耳量測、高解析度X光繞射儀、光致發光分析、原子力顯微鏡，以及掃描式電子顯微鏡。從以上所述的分析結果中可以發現在最高溫時成長的p型氮化鎵具有最佳的磊晶品質。
我們使用旋轉塗佈之方式並且在不同溫度以及在氮氣環境中於爐管中進行熱擴散，將p型氮化鎵轉變為n型氮化鎵。而實驗結果的最佳製程條件如下:分別是轉速為3000轉30秒、回火時間為30分鐘、回火溫度從300℃到900℃、回火時所使用的氣體為氮氣，並且使用二氧化矽蝕刻液浸泡70秒來將殘留的塗佈層去除。最後利用霍耳量測、光致發光分析、二次離子質譜儀來進行轉換過後的n型氮化鎵的特性分析。
從霍耳量測的結果中我們發現電子移動率的變化區間在200 cm2/V-s到350 cm2/V-s之間，而電子濃度的變化區間在1.5×1018 cm-3到 4.5×1018 cm-3之間均在300℃到 900℃的回火溫度條件下。我們發現當回火溫度為800℃時，可以得到最大的電子移動率。根據光致發光分析的結果，我們發現隨著回火溫度的上升，p型氮化鎵在430nm的強度慢慢遞減，而n型氮化鎵在370nm的強度慢慢遞增。同樣地從二次離子質譜儀的分析中我們發現隨著回火溫度的上升，矽的擴散深度也隨之增加。因此根據上述的結果所示，我們成功地利用旋轉塗佈之方式在爐管中進行熱擴散，來將p型氮化鎵轉變為n型氮化鎵。
接下來平面式的氮化鎵p-n接面光檢測器被製作完成，同樣使用旋轉塗佈之方式在爐管中800℃進行熱擴散。我們使用鎳/金(5nm/10nm)作為p型電極以及鈦/鋁/鈦/金(15nm/200nm/20nm/60nm)作為n型電極。而為了得到更好的光暗電流比以及更佳的元件特性，我們又另外製作一組元件是使用透明的氧化銦錫(100nm)來當作n型電極試圖藉此提升光電流。而從元件特性的量測中我們發現使用透明的氧化銦錫(100nm)來當作n型電極的元件確實具有較高的光電流、比較高的光暗電流比、比較高的紫外光對可見光比、較佳的檢測率以及更好的響應度。
而為了和我們這種新式的平面式氮化鎵p-n接面光檢測器做比較，我們又製作了一組傳統的垂直式p-i-n光檢測器來做比較。在此同樣利用有機金屬化學氣相沉積系統成長出Ⅲ-Ⅴ族p型和n型氮化鎵材料，而最上層p型氮化鎵的不同處在於它們的成長速度。之後這些試片被使用感應式電漿偶合機進行蝕刻至n型氮化鎵層來製作元件，同樣地使用鎳/金(5nm/10nm)作為p型電極以及鈦/鋁/鈦/金(15nm/200nm/20nm/60nm)作為n型電極。
而最後從以上這些實驗數據中，可以發現我們這種新式的平面式氮化鎵p-n接面光檢測器的元件特性可以近乎達到和傳統的垂直式p-i-n光檢測器的元件特性有相同的水準。

In this thesis, the p-GaN III-V alloys had been grown and characterized by metal organic chemical vapor deposition system (MOCVD). Several analysis techniques, such as Hall measurement, photoluminescence (PL), X-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM) had also been performed to characterize the crystal quality of these epitaxial p-GaN layers with different growth temperature. From these analysis results, we found that p-GaN layer with the highest growth temperature had the best crystal quality.
Diffusion by spin on dopant technique was used to convert the p-GaN into n-GaN by annealing process under nitrogen ambience for different temperatures. The optimal process parameters in converting p-GaN into n-GaN which were showed as follows: Spin speed (rpm) : 3000rpm for 30s, annealing time : 30mins, annealing temperature : 300℃~900℃, gas used during diffusion : nitrogen, remove dopant layer : BOE for 70s. Hall measurement, photoluminescence (PL) and secondary ion mass spectrometry (SIMS) had been performed to characterize the as-converted n-GaN layers.
From the Hall measurement, the electron mobility were about 200 cm2/V-s to 350 cm2/V-s, and the electron concentration were about 1.5×1018 cm-3 to 4.5×1018 cm-3 under different annealing temperature from 300℃ to 900℃. When annealing temperature was 800℃, the electron mobility was the largest. From photoluminescence (PL) spectra, we found that 430 nm belonged to p-GaN peak decreased and 370 nm belonged to n-GaN peak increased with increasing annealing temperatures. Also from SIMS analysis result, the depth of Si diffusion increased when annealing temperatures increased. We could find that p-GaN has been converted into n-GaN successfully by using spin on dopant technique.
Then planar GaN p-n junction photodetectors were fabricated by using spin on dopant technique under 800℃ diffusion. The photodetectors mentioned above were deposited Ni/Au(5nm/10nm) as p-contact and Ti/Al/Ti/Au(15nm/200nm/20nm/60nm) as n-contact. In order to get the better photo to dark current ratio and better device performance, we tried to deposit the transparent contact ITO (100nm) as n-contact and tried to increase the photo current of the photodetectors. It could be found that the samples with transparent contact ITO had a higher photo current, larger photo-to-dark current ratio, larger UV-to-Visible rejection ratio, better detectivity and better responsivity.
In order to compare with my novel planar p-n junction photodetectors, a conventional p-i-n photodetectors was fabricated. The samples were also grown by MOCVD, the top p-GaN layer of the samples with different growth rate, then the samples were under ICP dry etching to expose the n-GaN layer. Ni/Au (5nm/5nm) was deposited as p-contact and Ti/Al/Ti/Au (15nm/200nm/20nm/60nm) was deposited as n-contact.
From all experiment results, we could find that the device performance of the novel planar p-n junction photodetectors is nearly as well as conventional p-i-n photodetectors.

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