氧化鋅奈米柱紫外光導感測器及場效電晶體元件之研究

Investigation of ZnO Nanorod-Based UV Photoconductive Detectors and Field Effect Transistors

趙晚君(Wan-Chun Chao)

指導教授 ： 姬梁文

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2010年)

摘要

本論文主要研究可分為二個部份來探討，第一部分討論傳統式的氧化鋅薄膜(ZnO thin film)與一維型式(One-dimensional)氧化鋅奈米柱(ZnO nanorods, ZnO NRs)之紫外光導感測器(UV photoconductive Detectors, UV PDs)，並對薄膜以及直立式奈米柱做光響應度的特性分析。第二部分討論氧化鋅薄膜與氧化鋅奈米柱之場效電晶體(field-effect transistor, FET)在電性方面的表現。本實驗透過微影製程與和射頻磁控濺鍍(radio frequency magnetron sputtering, rf-sputtering)系統技術以及經由低溫水溶液方法達到選區成長氧化鋅奈米柱。
在光感測器部分，奈米柱元件所產生之光電流大於傳統薄膜元件,這可歸因於奈米助陣列的表面積大於薄膜型式。與傳統氧化鋅薄膜光感測器比較，在5伏特與370nm照光情況下的光靈敏度分別為287.73 and 0.11 A/W, 可見光互斥比(UV-to-visible rejection ratio; R360/R450)為76.8 and 183.45。
另一研究主題為氧化鋅場效電晶體(field-effect Transistor; FET)，我們組裝下閘極結構利用射頻磁控濺鍍技術製作氧化鋅薄膜作為通道層。為了找出最佳化，在氧化鋅電晶體中製作出不同厚度、退火、以及光響應之研究。另外，我們在玻璃機板上利用PMMA當作介界電層製作出上閘極結構之氧化鋅奈米柱電晶體。在上述所提到以氧化鋅為基材之電晶體表現出典型的金屬氧化物半導體場效電晶體(MOSFET)特性。不論如何，在這些研究中經由簡單以及低成本的技術可製作出氧化鋅為基材的元件，在未來具備將發展整合光電積體電路(OEIC, OptoElectronic Integrated Circuits)。

關鍵字

氧化鋅奈米柱 ； 紫外光導感測器 ； 場效電晶體

並列摘要

This dissertation is divided into two parts; one part discusses the characteristic of the photoresponse in conventional ZnO thin film and one-dimensional nanorods (NRs)-based UV photoconductive Detectors (UV PDs), respectively. Another discusses the electrical characteristic of ZnO thin film and NRs field-effect transistors (FET). This experiment demonstrates the photolithography and radio frequency magnetron sputtering (rf-sputtering) approach for using low-temperature solution method to achieve selective growth of ZnO NRs.
In the discussion of photoconductive PDs, the photocurrents generated from NR devices are increased much more than the conventional film devices, which could be attributed to the NR arrays having larger surface area than film. Compared with conventional PDs based on ZnO films, the photoresponsities with 5 V applied bias under 370-nm illumination were 287.73 and 0.11 A/W, and the ratios of UV to visible rejection were 76.8 and 183.45, respectively.
In the part of ZnO-based field-effect transistors, we fabricate bottom-gate structure using ZnO film as an active channel layer grown by using rf-sputtering. In order to find the optimum performance, ZnO transistors with different thicknesses of the active layer, annealing, and spectral responses were fabricated and investigated. Additionally, we fabricate top-gate ZnO NRs transistors with a poly (methyl methacrylate) (PMMA) gate dielectric on a glass substrate. Above-mentioned ZnO-based transistors, these devices exhibited the typical (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET), MOSFET characteristic. However, these researches reveal that ZnO-Based devices produced by a simple and low-cost technique, which could be applicable to the Optoelectronic Integrating Circuit (OEIC) in future.

並列關鍵字

ZnO nanorods ； UV photoconductive detectors ； field-effect transistor

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