21 research outputs found
[[alternative]]Barrier option approach for threshold's change in IFRS : the case of Taiwan
碩士[[abstract]]本文研究目的為利用障礙選擇權探討採用IFRS後對台灣上市櫃公司信用風險的影響,其障礙選擇權模型違約機率之差異。由於國內外許多文獻已證明:使用GAAP財報資料時,障礙選擇權預測公司違約風險的能力優於KMV模型,而台灣已於2013年推動新的會計準則IFRS,本文想探討其障礙選擇權的預測違約能力是否會有所改變?本文資料來源為2008年~2015年的台灣經濟新報資料庫(TEJ)的1595家公司(1377家正常營運的公司、96家曾發生財務危機的公司)。而本文研究步驟為分析台灣上市櫃公司各產業的GAAP與IFRS的障礙選擇權違約機率,並使用檢定力曲線以及Logit二元迴歸檢定各種產業的狀況。實證顯示:不論是GAAP或是IFRS的財報資料,其門檻負債比、檢定力曲線以及Logit二元迴歸都沒有明顯的差異。[[abstract]]This study’s purpose is investigating the influence of credit risk and the difference of default probabilities in Taiwan by Barrier Option after IFRS was used. Many literatures had proved that Barrier Option had better performance than KMV model when using GAAP financial data to predict default risk. In 2013, Taiwan promoted new accounting principles, IFRS. Therefore, we are wondering if the predicting ability of Barrier Option will have some changes.The samples are 1595 companies’ yearly data (including 1377 normal companies and 96 companies which had financial crisis before) from 2008 to 2015. And the research steps are examining the Barrier Option default probabilities of GAAP and IFRS in Taiwan Market first, then judging the industry situations by using power curve and logistic regression model.The empirical result found that no matter the data from GAAP or IFRS, there was no obvious difference between barrier-debt ratio, power curve, and logistic regression model.[[tableofcontents]]第一章 緒論 1
第一節 研究動機 1
第二節 研究目的 4
第三節 研究架構及流程 5
第二章 文獻探討 7
第一節、信用評等制度 7
第二節、結構式模型 8
第三節、縮減式模型 11
第三章 研究方法 14
第一節 KMV之信用風險模型 14
第二節 運用障礙選擇權-下出局式選擇權(DOWN-AND-OUT CALL OPTION) 18
第三節 信用風險模型預測能力比較 22
第四節 資料來源與說明 23
第四章 實證分析 25
第一節 檢定隱含的門檻是否存在 25
第二節 基本統計量 28
第三節迴歸分析 34
第五章 結論 37
附錄 38
參考文獻 41
圖目錄
圖表 1KMV模型架構圖 17
圖表 2預期違約機率示意圖 18
圖表 3誤差方程式變數區間 21[[note]]學號: 603531038, 學年度: 10
Using K-means and Self-Organizing Map to Analyze Heart Rate for Supporting Tele-Healthcare
[[abstract]]近年來老年人口的快速成長,以至於老人照護的相關議題也跟著被重視了起來,隨著科技與資訊技術的日新月異,使得我們可以在不久的將來透過網際網路做即時的遠距健康照護。有別於傳統的醫療照護儀器,遠距健康照護為老人在自己的家裡透過網際網路與照護系統進行長期、非察覺性的健康監測。但在遠距監測時,受測者的生理指數範圍將會比目前所定義的健康正常指數範圍來得大,並且具有許多因日常活動所造成的起伏變化,所以本研究提出一個有學習能力的生理分析系統。此系統在學習階段,將網際網路所傳送過來的老人健康生理指數利用叢集分析中的K均值法與類神經網路中的自組織映射圖(Self-Organizing Map, SOM),進行學習與分析,再由醫師或照護人員依照學習後的分類結果詢問受測者每組類別中所做過的日常活動。這些個人專屬的生理指數資料,可用來解決因為照護階段所測得指數範圍擴大過度提出警告的問題;並且當受測者健康狀況有惡化徵兆時即能做出正確的預測,告知醫護人員以便做及時的處理,以達到老人健康照護的目的。本論文的重點在生理指數的學習與分析,實驗結果說明所提方法之可行性
含解約權之附保證變額壽險評價分析
本文針對躉繳保費的附保證變額壽險進行評價,保單形式為生死合險,假設投保人可將期初的投資金額連結到兩種投資標的:股價指數及債券型基金,並以BGM模型描述利率的動態過程,然後分別計算不含解約權及含解約權的附保證變額壽險躉繳保費,進而求算出隱含在保單中的保證價值和解約權價值。針對含解約權的附保證變額壽險,以Longstaff and Schwartz(2001)提出的最小平方蒙地卡羅法處理解約的問題。最後,我們求算不同年齡下的男性保費,並且在投資比例、起始最低保證、最低保證給付成長率、針對解約的保證給付成長率和第一個允許的解約時點變動下,分別討論對於保證價值和解約權價值的影響。
結果顯示:(1)當起始最低保證給付等於期初投資金額時,投資在股票的比例越大,越能凸顯保證價值和解約權價值佔保費的比重。以30歲男性為例,保證價值佔不含解約權之附保證變額壽險的比例,由全部投資在債券型基金的0.03%,成長到全部投資在股票的13.86%;而解約權價值佔含解約權之附保證變額壽險的比例,由全部投資在債券型基金的0.05%,成長到全部投資在股票的9.12%。(2)投資比例、起始最低保證給付和最低保證給付成長率越大,保證價值越高。(3)起始最低保證給付和針對解約的保證給付成長率越大,解約權價值越大;而最低保證給付成長率和第一個允許的解約時點越大,解約權價值越小。(4)投資比例隨著最低保證給付不同對解約權價值有不同的影響。
關鍵字:附保證變額壽險、BGM利率模型、解約選擇權、最小平方蒙地卡羅法This study emphasizes on the pricing of variable life insurance with minimum guarantees. As an endowment policy in a single premium form, in this paper, it is assumed that the insured can distribute the initial investment amount into two underlying assets: the stock index fund and bond fund. Simulating the interest rate under a BGM model, computational procedures are performed for the single premium of the variable life insurance policy without surrender option and embedding a surrender option, and further, the guarantee value and surrender value embedded in the insurance policy. For the variable life insurance policy embedding a surrender option, the Least Square Monte-Carlo method proposed by Longstaff and Schwartz (2001) is applied to solve the surrender conditions. Finally, we calculate the premium for a male at different ages, and respectively analyze the variations of the guarantee value and surrender value under the influence of the investment portfolio, the initial minimum guaranteed amount, the growth rate of the minimum guarantee, the growth rate of the minimum guarantee for surrender and the first permitted surrender time.
The results show that: (1) when the initial minimum guaranteed amount equals the initial investment amount, higher proportion invested in stock will result in larger percentage of the guarantee value and surrender value to total premium. Take a 30-year old male as an example: the percentage of guarantee value to the premium of variable life insurance with minimum guarantee and without a surrender option, which is 0.03% when the initial investment amount thoroughly goes to bond fund, rises up to 13.86% with the entire amount invested in stock index fund. Likewise, the percentage of surrender value to the premium of variable life insurance with minimum guarantee and surrender option is 0.05% with total amount invested in bond fund, while it is 9.12% with the entire amount invested in stock index fund. (2) The higher proportion invested in stock, the initial minimum guaranteed amount and the growth rate of minimum guaranteed amount, the larger guarantee value. (3) Larger initial minimum guaranteed amount and the growth rate of the minimum guaranteed amount for surrender would contribute to a higher surrender value. The higher growth rate of the minimum guaranteed amount and the first permitted surrender time, the lower surrender value. (4) The influence of the investment portfolio to surrender value depends on the initial minimum guaranteed amount.
Key words: Variable life insurance with minimum guaranteed amount, BGM interest rate model, surrender option, least squares Monte Carlo approach
影像辨識神經網路應用於愛文芒果不良品分析與預測
<p>本研究採用Mask R-CNN影像辨識演算法模型以及Detectron2框架,應用於愛文芒果影像進行五類不良品分類。主旨在於針對愛文芒果五類不同病種進行多物件實例分割影像辨識,五類病種分別為著色不良、炭疽病、乳汁吸附、機械傷害以及黑斑病,總共五類不良病種。因廠商提供之資料集(training set + validation set共計59650張)資料雜訊嚴重,在資料清洗(Data Cleaning)以及資料前處理(Data Preprocessing)階段花費超過500小時以上,以及將不良資料汰除8995張,最終資料集共為50655張。資料集蒐集不易以及資料雜訊多的情形,為人工智慧應用於真實場域所會面臨的挑戰。為求辨識精準度而非速度,此研究主要應用技術為深度神經網路影像辨識演算法 Mask R-CNN以及基於COCO Dataset Pretrained Model應用遷移式學習(Transfer Learning)。再運用GrabCut演算法,在資料前處理階段使實例分割(Instance Segmentation)達到99.9%的精準度。以及應用X101-FPN骨幹,以增加神經網路深度,相較R50-PFN,使辨識精準有效提升90%,最終達成67.2之AP。</p>
<p>&nbsp;</p><p>This paper used the image recognition algorithm model and Detectron2 framework to detect five types of defective Irwin mangos. The principal object was to recognize five different diseases concerning Irwin mangos by multi-object instance segmentation. There are five diseases respectively, poor coloration, anthrax, latex attached, mechanical harming and ink spot disease. We spent over 500 hours on data cleaning and data pre-processing due to the dataset (training set + validation set totally 59650 images) offered by vendor is inferior in quality. We also eliminated 8995 bad images. Finally, the dataset remained 50655 images. Data collection and data hazard are the significant challenges will face when apply AI to the real-world. Our research mainly used Mask R-CNN which is the image recognition algorithm of deep neural networks and transfer learning based on COCO Dataset Pretrained Model makes the detection results more precise. Then, we used Grabcut algorithm which makes accuracy of instance segmentation up to 99.9% in data pre-processing stage. Further, we applied X101-FPN backbone for making neural network deeper which compared to R50-FPN was effectively improved 90% accuracy. Eventually, we achieve the 67.2 AP in ours experiment.</p>
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Construction and Development of the Principles for Deep Knowledge by Habitual Domains Abilities Index and the Industrial Employee Core Abilities Index
不同於以往,近年來不僅天災頻傳、自然資源日漸匱乏,世界末日之說更是甚囂塵上。 牽動的是整體經濟大環境之巨變,過去榮景不再,景氣復甦牛步,春燕遲未歸來。M型化社會競爭激烈,一切講求效率,變化迅速,殘酷現實,物競天擇,適者生存,提升自我競爭力始能在此人生沙場上保有一席之地,從自身經驗中學習將逐漸被淘汰,學習成功人士的經驗與智慧不失為一個效率頗高的學習方式。 因此,本研究將沿用「賈伯斯之創新九個深智慧集合表」 (林威廷,2011)其中所提出之九個對應深智慧原理 (游伯龍,2011)的能力集合,建構「習慣領域深智慧能力指標」。 研究之流程將分為三階段: 第一階段將使文獻分析法,沿用並分析整理數位當今成功人士之個人特質與態度,對照「賈伯斯之創新九個深智慧集合表」 (林威廷,2011),以達內容效度。 第二階段旨為整理培養能力集合之方法,運用第一階段所有經分析整理之能力集合,建立習慣領域深智慧能力指標量表,整合對7位習慣領域學會成員對於此量表之建議且修正,達專家效度。最後,將第二階段完成之能力指標量表問卷,交由大學高階經理人碩士專班學生及全職碩士班學生共225名進行分析,以完成本研究目的之「習慣領域深智慧能力指標」與信效度測試。
研究結果顯示,業界菁英與全職碩士班學生在低深原理、循環進化原理、內部聯繫原理、矛盾原理的態度上存在著顯著差異。 而男性與女性在循環進化原理、內部聯繫原理、矛盾原理上也會有所不同。此外,曾經上過習慣領域相關課程與否,在內部聯繫原理、裂與痕原理的態度上存在著顯著差異。期待透過此一能力指標的建立未來可實際運用成為企業徵才參考依據之一。Mother earth has been crying recently, the environment we live in nowadays has been changed dramatically; even the rumor of 2012 Judgment Day has been spread all over the world. What comes along is the global economic crisis; the best of times is no longer with us, recession instead. Life is full of struggles and injustice in such an “M-shaped society”. Therefore, one of the best and efficient ways for survival is to improve ourselves by learning characteristics and attitude from outstanding people, some tycoons, for instance. The study will apply the nine characteristics from “The Characteristics Index of Steve Jobs by Principles for Deep Knowledge of Habitual Domains” (Lin, 2011), then develop an Abilities Index by Principles for Deep Knowledge of Habitual Domains , combining with the suggestions from seven members of The Habitual Domain Association , to reach the professional validity. Then finally make 225 graduate school and EMBA students to take the reliability and validity of the abilities index. The purpose of the study is to construct an abilities index by Principles for Deep Knowledge of Habitual Domains.
The result shows that there are significant differences between EMBA students and graduate school students on attitude of some deep knowledge. Besides, there are significant differences between genders on attitude of some deep knowledge. And also the students who have join the class of Habitual Domain or not are significant differences on attitude of some deep knowledge.
Hopefully this index could be considered as a helpful reference for employment and make practical use.目次
1. 緒論 1
1.1. 研究背景 1
1.2. 研究目的 3
1.3. 研究價值 3
2. 文獻探討 4
2.1. 習慣領域學說 4
2.2. 深智慧原理 5
3. 研究方法 9
3.1. 研究對象 9
3.2. 研究工具與流程 9
4. 結果與討論 10
4.1. 描述性統計 10
4.2. 習慣領域能力指標量表 15
4.3. 習慣領域深智慧能力指標相關分析 15
4.4. 習慣領域深智慧能力指標差異性分析 17
5. 結論與建議 22
5.1. 研究發現 22
5.2. 結論 23
5.3. 未來研究建議 24
參考文獻 25
附錄 26
附錄1.習慣領域能力指標量表(專家效度) 2
Preparation of Organic-Inorganic Oxide Hybrid Composite with Amine Coordination
[[abstract]]研究中使用鋰鈮鎢氧化合物與鹽酸溶液進行離子置換,製成水合鈮鎢氧化合物作為前驅物。經由六氨鈷離子插層入水合鈮鎢氧化合物實驗中,確認水合氨基離子為可撐層的配位化合物。同時並利用苯二胺三種同分異構物,其胺基對水分子的作用力不同而造成水分子對苯二胺包覆程度不同的特性,探討水合作用力是否為苯二胺同分異構物插層入水合鈮鎢氧化合物結構的決定因子。經XRD分析後,證明鄰、間、對三種異構物皆可插層入水合鈮鎢氧化合物結構中。研究中也首次證明可利用雷射蒸鍍的方式形成鋰鈮鎢氧化合物薄膜,並試圖經酸置換形成水合鈮鎢氧化合物薄膜,期望能形成一有機無機複合透明薄膜電極。[[abstract]]The protonated HNbWO6‧1.5H2O powder prepared by ion-exchanged of LiNbWO6 in acid solution is used as the precursor for chemical synthesis of organic-inorganic oxide hybrid structure. Ion exchanged [Co(NH3)6]0.1NbWO6 compound with expanded lattice demonstrates the feasibility of amine coordination in protonated HNbWO6‧1.5H2O. Three isomers of phenylenediamine with different hydrability are applied to investigate the determination factor of ion exchange reaction. Intercalated isomeric compounds display novel organic-inorganic oxide hybrid structures with different appearance. Thin film electrode of LiNbWO6 grown by pulsed laser deposition technique is demonstrated in this work. However, a transparent organic-inorganic oxide thin film electrode requires more efforts in future to develop a proper environment for ion exchange reaction.[[note]]碩
A study of Variable Step-Size Algorithms in Active Noise Control Systems with or without Disturbance
主動噪音控制系統在實際應用中,環境的改變將會影響主動噪音控制的性能。為了處理環境改變的問題,本文提出了兩種可變步長正規化LMS演算法,一種是以殘留誤差直接調整步長的型式,另一種是以適應性方法更新步長的型式。並以一個已建立的決定論方法進一步分析可變步長正規化演算法,使得分析出的條件在主動噪音控制中能確保演算法可以收斂。而在電腦模擬中,我們考慮四種情況,包含改變主噪音源之振幅、改變主噪音源之頻率、改變第一路徑或改變第二路徑的情況。由模擬結果可得知,應用本文所提出的可變步長演算法於這些環境改變的情況之下,可以有效保持主動噪音控制之消音性能,並實現演算法的可行性。In practical active noise control (ANC) systems, environmental changes will affect ANC performance. This study proposes two kinds of variable step sizes (VSSs) for the normalized LMS (NLMS) algorithms to deal with the problems caused by environmental changes. One uses a residual error directly to tune step size, while another uses an adaptive method to update step size. A deterministic method is then established to analyze the VSS-based NLMS algorithms such that conditions to ensure convergence of the algorithms in ANC systems can be derived. Four kinds of environmental changes, including change in amplitudes of the primary noise, change in frequencies of the primary noise, change of the primary path, and change of the secondary path, are considered in computer simulations. Simulation results show that the VSS-based algorithms can maintain effective ANC performance under these environmental changes and thus support the feasibility of the proposed VSSs.誌謝………………………………………………………………………I
摘要………………………………………………………………………II
ABSTRACT ………………………………………………………………III
論文目錄…………………………………………………………………IV
圖目錄……………………………………………………………………VI
表目………………………………………………………………………X
第一章 緒論……………………………………………………………1
1.1 研究動機………………………………………………………1
1.2 文獻回顧………………………………………………………1
1.3 論文概要………………………………………………………4
第二章 可變步長演算法於無干擾之主動噪音控制系統……………6
2.1 無干擾之主動噪音控制系統的描述…………………………6
2.2 NFxLMS/CE 演算法之介紹……………………………………8
2.3 Vss-NFxLMS/CE演算法…………………………………………9
2.3.1 Vs1-NFxLMS/CE演算法步長參數之範圍……………………10
2.3.2 Vs2-NFxLMS/CE演算法步長參數之範圍……………………12
第三章 可變步長演算法於有干擾之主動噪音控制系統……………14
3.1 具有干擾之主動噪音控制系統的描述………………………14
3.2 NFxLMS/CE_DC演算法之介紹…………………………………15
3.3 Vss-NFxLMS/CE_DC演算法……………………………………18
第四章 無干擾時主動噪音控制之電腦模擬…………………………19
4.1 Vs1-NFxLMS/CE演算法之多頻模擬…………………………23
4.2 Vs2-NFxLMS/CE演算法之多頻模擬…………………………28
4.3 EDSS-NFxLMS/CE之多頻模擬…………………………………33
4.4 模擬比較與討論………………………………………………37
第五章 有干擾時主動噪音控制之電腦模擬…………………………38
5.1 Vs1-NFxLMS/CE_DC演算法之多頻模擬………………………40
5.1.1 改變噪音源(振幅)……………………………………………44
5.1.2 改變噪音源(頻率)……………………………………………46
5.1.3 改變第一路徑…………………………………………………48
5.1.4 改變第二路徑…………………………………………………50
5.2 Vs2-NFxLMS/CE_DC演算法之多頻模擬………………………52
5.2.1 改變噪音源(振幅)……………………………………………56
5.2.2 改變噪音源(頻率)……………………………………………58
5.2.3 改變第一路徑…………………………………………………60
5.2.4 改變第二路徑…………………………………………………62
5.3 EDSS-NFxLMS/CE_DC之多頻模擬……………………………64
5.3.1 改變噪音源(振幅)……………………………………………67
5.3.2 改變噪音源(頻率)……………………………………………68
5.3.3 改變第一路徑…………………………………………………70
5.3.4 改變第二路徑…………………………………………………71
5.4 模擬比較與討論………………………………………………73
第六章 結論與未來展望………………………………………………77
6.1 結論……………………………………………………………77
6.2 未來展望………………………………………………………77
參考文獻…………………………………………………………………7
Effect of Crystallography-Etched Facets of Patterned Sapphire Substrates on Performance of GaN-Based LEDs
為了降低差排密度與提升光取出率,本論文主要利用黃光微影技術配合濕蝕刻製程製作圖案化藍寶石基板。我們在光罩上設計不同大小與間距的圖案來分析藍寶石基板圖案大小與間距對於元件光強度的影響。圖案大小與間距將影響濕蝕刻後藍寶石基板總表面積,藍寶石基板表面積的增加將能增加光萃取率而濕蝕刻產生之晶體蝕刻面能降低氮化鎵磊晶膜差排密度。因此嘗試製作一種晶體蝕刻面最大化的圖案化藍寶石基板,並對其磊晶膜進行品質與特性分析。
我們得到圖案化藍寶石基板氮化鎵磊晶膜最佳rocking curve半高寬值於對稱面(002)面為283 arcsec,非對稱面(102)面為274 arcsec。在350mA電流注入下圖案化藍寶石發光二極體比一般藍寶石發光二極體光輸出功率提升約40%,光強度提升約108%。此提升除了因為缺陷密度下降使得內部量子效率提升,另一方面也因為晶體蝕刻面能有效提高其光取出效率。藉由穿透式電子顯微鏡,發現氮化鎵磊晶膜內部差排彎曲集中並形成規則性排列,這是氮化鎵磊晶膜品質改善的證明。In this thesis, in order to decrease the threading dislocation density (TDD) and enhance the light extraction efficiency, we used the photolithography technology and wet-etching process to fabricate patterned sapphire substrates. We design the mask pattern with different size and spacing and to investigate the effect of different patterned sapphire substrate on light intensity. It was found that the mask pattern size and spacing will affect the c-plane ratio. Sapphire surface area will increase the rate of increase in light extraction. Crystallography-etched facets can reduce the dislocation density. So we try to design a kind of patterned sapphire substrate. The best full width at half maximum (FWHM) of GaN rocking curve symmetric (002) and asymmetric (102) are 283 and 274 arcsec, respectively. Under a 350mA current injection current, the output power of the stripe patterned sapphire subtrate LED is enhanced by 40% and light intensity increased about 108% as compared with that of the conventional LED. These results indicated that the decreased dislocation density could enhance the internal quantum efficiency and the Crystal lography-etched facets could improve the light extraction efficiency. By transmission electron microscopy(TEM) we found the dislocations bending and regular arrangement of the formation, which proved to improve the quality of GaN epitaxial films.目錄
書名頁
審核頁
授權書
誌謝
誌謝 i
中文摘要 ii
Abstract iii
目錄 iv
表目錄 viii
圖目錄 ix
第一章 概論 1
1-1 前言 1
1-2 研究背景 2
1-3 研究動機與目的 3
第二章 理論基礎與文獻回顧 6
2-1 氮化鎵磊晶膜與藍寶石基板之關係 6
2-1-1 III-V 族氮化物材料結構特性簡介 6
2-1-2 藍寶石基板與氮化鎵磊晶膜結構之差異 6
2-2 有機金屬氣相沉積磊晶原理 8
2-3 貫穿式差排形成機制與影響 8
2-4 氮化鎵蝕刻孔穴與差排種類之關係 10
2-5元件效率與光取出率關係 11
2-6 藍寶石基板濕蝕刻技術原理 13
第三章 實驗步驟與分析設備 15
3-1 前言 15
3-2 實驗規劃與流程 15
3-2-1 圖案化藍寶石基板之製作 15
3-2-2 光罩圖形定義 16
3-2-3 MOCVD 成長LED 結構 17
3-2-4 選擇性蝕刻氮化鎵磊晶膜形貌的建立 18
3-3 分析設備簡述與原理 18
3-3-1 掃描式電子顯微鏡 18
3-3-2 原子力顯微鏡 19
3-3-3 穿透式電子顯微鏡 19
3-3-4 X光繞射光譜儀 20
3-3-5 光激發光譜分析儀 21
3-3-6 電性量測系統 21
3-4 光學模擬軟體 21
3-5 元件切割、打線與封裝 23
第四章 實驗結果與討論 24
4-1 前言 24
4-2 角錐狀Triangle圖案大小與圖案間距關係 24
4-4 條狀Stripe藍寶石基板 26
4-5 X光繞射法之半高寬(XRD) 28
4-6 氮化鎵磊晶膜之穿透式電子顯微鏡分析 29
4-7 氮化鎵磊晶膜之蝕刻孔洞密度分析 30
4-8 藍光發光二極體發之光電特性量測 30
4-9 藍光發光二極體光輸出功率、效率 31
4-10 藍光發光二極體內、外部量子效率 32
第五章 結論與未來展望 33
參考文獻 35
表目錄
表2-1 三族氮化物其性質比較(W): Wurtzite (Z): Zincblende 39
表 2-2 異質磊晶的主要問題 39
表 3-1 電漿輔助化學氣相沉積二氧化矽薄膜之沉積條件 40
表 3-2 感應偶合電漿蝕刻二氧化矽薄膜之蝕刻條件 40
表 3-3 BOE稀釋液蝕刻二氧化矽薄膜之蝕刻條件 40
表 4-1 Trace-pro光學模擬條件 40
表 4-2 Stripe藍寶石基板氮化鎵磊晶膜XRD rocking curve半高寬 41
表 4-3 Triangle藍寶石基板氮化鎵磊晶膜XRD rocking curve半高寬 41
表 4-4 各種圖形總表面積與光強度關係 41
表 4-5 Stripe藍寶石基板晶面與c-plane夾角角度 42
表 4-6 Stripe藍寶石基板氮化鎵磊晶膜XRD rocking curve半高寬 42
表 4-6 Stripe藍寶石基板氮化鎵磊晶膜XRD rocking curve半高寬 42
圖目錄
圖 2-1 (a) Wurtzite GaN結構 (b) Zincblende GaN結構示意圖 43
圖 2-2 異質磊晶結構晶格不匹配現象之橫截面示意圖 43
圖 2-3 氮化物半導體和各種基板之晶格常數與能隙關係圖 44
圖 2-4 氮化鎵與藍寶石基板間原子相對位置關係 44
圖 2-5 兩路(Two-Flow)長晶示意圖 44
圖 2-6 兩路(Two-Flow)長晶的氣體流向示意圖 45
圖2-7 基板表面延伸生長差排示意圖 46
圖2-8 氮化鎵二極體結構內部之差排型態示意圖 46
圖2-9 (a) 氮化鎵磊晶膜表面被蝕刻後之SEM圖 (b) 氮化鎵磊晶膜表面被蝕刻後之AFM圖 (c) α、β、γ三種蝕刻孔洞之側向形貌示意圖 (d) α蝕刻孔洞之TEM剖面圖 (e) β蝕刻孔洞之TEM剖面圖 47
圖 2-10 氮化鎵發光二極體之光取出限制圖...........................................................48
圖 2-11 圖案化藍寶石基板改善出光模擬圖...........................................................48
圖 3-1 圖案化藍寶石基板製作流程圖..........................................................49
圖 3-2 光罩設計圖...................................................................................................50
圖 3-3 藍寶石基板表面形貌OM圖.......................................................................51
圖 3-4 氮化鎵磊晶層製程溫度與時間關係圖 (a) 第一層氮化鎵磊晶層 (b) 第二層氮化鎵磊晶層......................................................................................................52
圖 3-5 掃描式電子顯微鏡系統示意圖...................................................................53
圖 3-6 原子力顯微鏡量測系統示意圖 54
圖 3-7 穿透式電子顯微鏡系統示意圖 55
圖 3-8 X光繞射光譜儀系統圖示意圖 56
圖 3-9 (a) 晶格散漫示意圖 (b) omega掃描示意圖 (c) X光繞射系統之光學模組構造圖 57
圖 3-10 光激發光光譜量測系統示意圖 58
圖 3-11 光激發光輻射再結合過程示意圖 58
圖 4-1一般藍寶石基板發光二極體燭光角度圖 59
圖 4-2 P4-2藍寶石基板發光二極體燭光角度圖 60
圖 4-3 P4-4一般藍寶石基板發光二極體燭光角度圖 60
圖 4-4 P2-4藍寶石基板發光二極體燭光角度圖 61
圖 4-5 P 2-2藍寶石基板發光二極體燭光角度圖 61
圖 4-6 P4-4藍寶石基板發光二極AFM與SEM圖 62
圖 4-7 P4-2藍寶石基板發光二極AFM與SEM圖 62
圖 4-8 P2-2藍寶石基板發光二極AFM與SEM圖 63
圖 4-9 P2-4藍寶石基板發光二極AFM與SEM圖 63
圖4-10 掃描式電子顯微鏡(a)藍寶石表面微結構形貌(b)-(e)為MOCVD成長30分鐘(f)為MOCVD成長90分鐘磊晶膜表面形貌 65
圖 4-11 Triangle藍寶石圖案側像圖(a)P4-4(b)P4-2(c)P2-2(d)P2-4 ..66
圖 4-12 Triangle藍寶石不同圖案大小與間距基板成長未參雜氮化鎵磊晶膜之XRD rocking curve圖(a)(002)對稱面與(b)(102)不對稱面 67
圖 4-13 Triangle藍寶石基板不同圖案大小與間距對發光二極體電流-發光強度影響特性圖 68
圖4-14 3μm條狀二氧化矽阻擋層示意圖 69
圖4-15 3μm光罩圖形之OM圖 69
圖4-16 蝕刻條紋沿著藍寶石方向之氮化鎵磊晶膜SEM剖面圖(a)一次蝕刻10分鐘二次蝕刻5分鐘(b)一次蝕刻10分鐘二次蝕刻10分鐘 70
圖4-17 Stripe藍寶石基板SEM剖面圖(a)一次蝕刻5分鐘(b)一次蝕刻5分鐘二次蝕刻2.5分鐘(c)一次蝕刻5分鐘二次蝕刻5分鐘 71
圖4-18 Stripe藍寶石基板SEM剖面圖(a)一次蝕刻10分鐘(b)一次蝕刻10分鐘二次蝕刻2.5分鐘(c)一次蝕刻10分鐘二次蝕刻5分鐘 72
圖4-19 Stripe藍寶石基板氮化鎵磊晶膜SEM剖面圖(a)一次蝕刻10分鐘二次蝕刻5分鐘(b)一次蝕刻10分鐘二次蝕刻10分鐘(c)一次蝕刻10分鐘二次蝕刻15分鐘 73
圖 4-20 Stripe藍寶石基板發光二極體燭光角度圖 74
圖 4-21 Stripe藍寶石基板發光二極AFM與SEM圖 74
圖4-22 Stripe藍寶石不同圖案高度基板成長未參雜氮化鎵磊晶膜之XRD rocking curve圖(a)(002)對稱面與(b)(102)不對稱面 75
圖4-23 1.1μm Stripe 與一般藍寶石基板成長發光二極體結構磊晶膜之XRD rocking curve圖(a)(002)對稱面與(b)(102)不對稱面 76
圖4-24 Stripe藍寶石基板氮化鎵磊晶膜差排彎曲TEM截面圖 77
圖4-25 Stripe藍寶石基板氮化鎵磊晶膜差排選擇性蝕刻缺陷集中SEM圖 78
圖4-26 蝕刻孔洞密度圖(a)CSS(b)1.3μm stripe-pss(c)1.1μm stripe-pss(d)0.9μm stripe-pss 80
圖4-27 變溫PL量測(a)一般藍寶石基板(b)Stripe藍寶石基板發光二極體之內部量子效率 81
圖4-28 Stripe與一般藍寶石基板發光二極體電壓-電流特性曲線(a)順向電壓(b)逆向電壓 82
圖4-29 Stripe與一般藍寶石基板發光二極體光功率輸出圖(a)封裝前(b)封裝後 83
圖4-30 Stripe與一般藍寶石基板發光二極體電流-發光強度特性圖 84
圖4-31 Stripe與一般藍寶石基板發光二極體光電轉換效率圖 8
Water-vapor-doped Graphene for Temperature Sensor
本研究用石墨烯作為感測元件以設計溫度感測器。由化學氣相沉積法成長之少層石墨烯,以手機保護貼為轉印基材將其轉印於玻璃上,製成溫度感測器,分別於大氣環境、真空環境、水氣環境三種環境中進行電阻對溫度變化的量測,並且藉由氫原子摻雜的前置步驟使石墨烯對水氣的吸附能力和吸附速率提升。電阻由Agilent 34411A之萬用電表量測,溫度由三段式高溫爐控制,最後經由計算得到溫度感測器於各環境下之溫度電阻係數(TCR),並藉此分析其溫度感測的性質。 研究結果得到,一般大氣環境中重摻雜石墨烯之TCR值容易受環境的影響,其溫度感測能力不佳。真空環境中純質石墨烯為負溫度電阻係數(NTC),且TCR值為定值,即感測器之靈敏度穩定。而水氣輕摻雜之石墨烯為NTC性質,其|TCR|隨溫度上升而變大,即溫度越高感測器之靈敏度越佳,至於水氣重摻雜時則為PTC性質。另外,氫原子摻雜後的水氣輕摻雜之石墨烯有最大的溫度感測靈敏度,其|TCR|於65 ℃時約為0.35 %/℃。Graphene was taken as the sensing element to design a new temperature sensor in this study. Temperature sensor was made by the few-layer graphene which was grown by chemical vapor deposition (CVD) and then transferred to glass as the transfer substrate. We measured the relationship between temperature and resistance under normal atmospheric environment, vacuum environment and water vapor environment with hydrogen-doping preprocess respectively. Then we calculated temperature coefficient of resistance (TCR) of these cases and analyzed their temperature sensing behaviors. The experimental result indicates that the graphene has poor temperature sensing property under normal atmospheric environment. Intrinsic graphene under vacuum environment is negative temperature coefficient (NTC) and its sensitivity is stable. Lightly-vapor-doped graphene has NTC as well. However, heavily-vapor-doped graphene is positive temperature coefficient (PTC). And the |TCR| or the sensitivity of lightly-vapor-doped graphene increases as temperature rises. Furthermore, hydrogen doping will increase absorption capacity and absorption rate of graphene, which causes larger |TCR|, about 0.35 %/℃ at 65 ℃
