以氮化鋁薄膜作為主動層之深紫外光檢測器之研製

陳炫旭(Hsuan-Hsu Chen)

指導教授 ： 熊京民 ； 楊茹媛

國立屏東科技大學/工學院/機械工程系所/碩士(2008年)

https://doi.org/10.6346/NPUST.2008.00187

摘要

本論文為研究應用於深紫外光之金屬-半導體-金屬(metal-semiconductor-metal)結構光檢測器，以氮化鋁薄膜作為主動層並深入研究其材料與光電特性。故，本論文主要分成三大部份：(a) 氮化鋁薄膜之製備與研究；(b) 指叉電極之設計；(c) 以氮化鋁為主動層製作指叉式金屬-半導體-金屬紫外光檢測器與量測。
(a) 氮化鋁薄膜之製備與研究
本論文製備一種可應用於紫外光檢測器之氮化鋁薄膜，並探討其薄膜之材料特性。該薄膜為能帶（energy gap）6.2 eV之高介電常數(k=8~10)半導體材料。在製程上，p型矽晶圓作為基板並以濺鍍製程為主，將針對薄膜厚度、靶材功率、氮氣/氬氣比作為製程變數，並探討其製程條件與材料特性上之關係，並配合三種不同厚度的氮化鋁薄膜，進行多種材料上的鑑定與分析；例如：結晶狀態、結晶方向和晶粒尺寸以XRD與Raman頻譜儀分析以及使用SEM和AFM觀察薄膜之斷面結構與表面粗糙度，用以確保該薄膜是否具有可實際應用於深紫外光檢測器之資格。
(b) 指叉式電極之設計
本論文設計了圓形結構之指叉式電極。經查閱文獻可知，方形指叉式電極較常應用在光檢測器中。然而，該類型之電極卻擁有一些缺點；例如：增加雜散電容，增大暗電流，特別是與光訊號來源無法達到良好之匹配。另外，電射光和發光二極管（ LED ）之聚焦光束皆是圓形分佈。因此，利用圓形結構電極之光檢測器會具有較優之光源匹配能力。
(c) 以氮化鋁為主動層之紫外光檢測器之製備與量測
本論文提出以氮化鋁為主動層之金屬-半導體-金屬結構紫外光檢測器，此結構可在紫外光區段產生快速響應與光暗電流比高於5個數量級(10-5 A - 10-10 A)之光檢測元件結構。在光電特性上，主要係以I-V量測儀量測光暗電流並配合分光儀光電響應量測系統，評估該元件之光電響應能力。最後，本論文亦對氮化鋁薄膜應用在光檢測器上，提出建議與未來工作方向。

關鍵字

氮化鋁 ； 金屬-半導體-金屬 ； 高介電常數 ； 光檢測器

並列摘要

In this thesis, we have studied the AlN thin film which is act as the active layer of metal-semiconductor-metal (MSM) structure for the deep UV photodetector. The thesis divided into three parts: (a) Preparation and procedure of AlN thin film；(b) design of interdigital electrode of the photodetector；(c) Measured results of the fabricated UV MSM photodetector.
(a) Preparation of AlN thin film
In the thesis, we propose a detailed fabricating process and characterization of AlN film UV photodetector. The AlN thin film has 6.2 eV energy gap and high dielectric constant (k=8~10). To deeply study the properties of AlN, we grouped into three main process conditions which are thickness, power, nitrogen/argon concentration ratio variations. To examine the AlN thin film, XRD and Raman measurements is performed for evaluating the crystalline quality. The surface and cross-section of AlN thin film were observed by AFM and SEM. To evaluate the film for actual application qualifications of the deep UV photodetector.
(b) Design of interdigital electrode
In the second part of the dissertation, we have designed the circular interdigital contact electrodes on fabricated AlN thin film. The currently used MSM photodetectors with rectangular interdigitated contacts have some disadvantages such as increased capacitance, degraded dark current and especially mismatch the integration with optical signal sources. Mo optical sources such as lasers and light emitting diodes (LEDs) have a circular distribution in nature. Therefore, the designed circular contact electrode is commonly used in general photodetector applications.
(c) Measured results of the fabricated UV MSM photodetector.
In the third part of the dissertation, the characteristics of proposed structure have fast responsivity and the ratio of photo / dark current is more than 5 orders of magnitude (10-5 A - 10-10 A). The ratio of photo / dark current was measurement by I-V system, and appraisal the feasibility that sputter deposition the AlN thin film on Si.
Finally, some useful suggestions and future works are made in AlN-based UV MSM photodetector applications.

並列關鍵字

AlN ； metal-semiconductor-metal (MSM) ； high dielectric constant ； photodetector

參考文獻

17. 劉晏綸（2006）超微奈米鑽石薄膜製作平面場發射元件與其電子場發射特性。國立清華大學材料科學工程學系碩士論文，13頁。

20. 簡維政（2004）氮化鎵上氮化鋁薄膜式表面聲波元件特性研究。私立中原大學電子工程學系碩士學位論文，9頁

3. 詹勳政（2006）碳離子佈值於氮化鋁鎵/氮化鎵異質接面金屬-半導體-金屬光偵測器之製作與研究。國立虎尾科技大學光電與材料科技研究所碩士論文，1-3頁。

8. E. Monroy, F. Calle, J. L. Pau, E. Munoz, F. Omnes, B. Beaumont, P. Gibart（2001）AlGaN-based UV photodetectors. Journal of Crystal Growth. 230:537-543.

9. O. M. Nayfeh, S. Rao, A. Smith, J. Therrien, and M. H. Nayfeh（2004）Thin film silicon nanoparticle UV photodetector. IEEE photonics technology letters. 16(8): 1927-1929.