非晶系銦鎵鋅氧化物與氧化鋅奈米柱網絡應用於光偵測器與電晶體之研究

Study of a-InGaZnO and ZnO Nanorod Networks for Photodetectors and Transistors

蔡其南(Chi-Nan Tsai)

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(2011年)

摘要

透明寬能隙和非晶型態氧化物半導體元件具有潛在可能成為下一世代元件。本論文主要研究為非晶型氧化銦鎵鋅和氧化鋅奈米柱網路之光檢測器(PDs)和電晶體(TFT)之光電元件製備與特性分析。其主要研究可分為兩個部分:
第一部分（材料和光感測器特性），我們研究了非晶型氧化鋅鎵銦和氧化鋅奈米結構之材料的光學、電特性。利用射頻磁控濺鍍(radio frequency magnetron sputtering, rf-sputtering)系統技術以及經由低溫水溶液方法沉積主動層。X-射線繞射光譜儀(XRD)，原子力顯微鏡(AFM)，以及場發射掃描式電子顯微鏡(FE-SEM)來觀察氧化鋅奈米柱(ZnO NRs)的表面形態及光學晶體結構。而且非晶型氧化鋅鎵銦與氧化鋅光檢測器皆製備在玻璃基板上。其實驗結果顯示非晶型氧化鋅鎵銦光檢測器比起薄膜型氧化鋅光檢測器有相對較低的漏電流和較高的紫外光到可見光的抑制比。
第二部分(電晶體之特性)，我們利用射頻磁控濺鍍在二氧化矽上的p型si機版沉積非晶型氧化鋅鎵銦薄膜做為通道層來製作下閘極結構的電晶體。為了去得到最佳特性，我們將探討不同厚度的非晶氧化鋅鎵銦薄膜，並且將其退火製作研究。我們也在玻璃基板上製作非晶氧化鋅鎵銦透明電晶體並利用了高介電係數材料二氧化鉿作為介電層。再將元件進行輸出和轉移特性的量測與分析。結果發現高介電係數二氧化鉿做閘極介電層會有較低的功率損耗，且在紫外光到可見光的範圍內具有較高透明性。此外，我們在玻璃基板製作上閘極結構的自組裝的氧化鋅奈米柱網路電晶體並利用了PMMA做為閘極介電層。這些氧化鋅奈米柱選區成長在源極與汲極的通道層之間。奈米柱網絡可以提供額外的電子傳輸路徑。實驗的結果顯示氧化鋅奈米柱網路可以透過操作汲極和閘極電壓來改變通道傳導性。不論如何，這些元件在下一世代的光電元件中具有潛在可能被廣泛的運用。

關鍵字

銦鎵氧化鋅 ； 氧化鋅 ； 氧化鋅奈米柱 ； 光檢測器 ； 電晶體

並列摘要

Wide-band-gap Transparent and amorphous oxide semiconductors are promising functional components for next-generation devices. This dissertation describes the fabrication and characterization of optoelectronic devices (photodetector (PDs) and transistors) with a-InGaZnO and ZnO nanorod (NR) networks. This main investigation is divided into two parts.
First (Material and PD Characteristics), we studied the optical and electrical properties of the a-InGaZnO and ZnO nanostructures materials. The active layers were deposited by radio frequency magnetron sputtering (rf-sputtering) approach and hydrothermal solution. Transmission, absorption, X-ray diffraction (XRD), atomic force microscopy (AFM), and field-emission scanning electron microscopy (FE-SEM) were then utilized to characterize the optical and crystallographic properties of the ZnO NRs. The a-InGaZnO and ZnO film PDs were also fabricated on glass substrates. Experimental results indicate that a-InGaZnO PDs have lower leakage current and higher UV-to-visible rejection ratio than the other ZnO film PDs.
Second (Transistors Characteristics), we fabricate top-gate structure using a-InGaZnO film as an active channel layer and deposited onto SiO2/p++-Si substrates by rf magnetron sputter deposition. In order to find the optimum performance, a-InGaZnO transistors with different thicknesses of the active layer, and annealing were fabricated and investigated. Additionally, we also describe the top-contact-type self-assembling ordered ZnO NR network transistors with a poly (methyl methacrylate) (PMMA) gate dielectric on a glass substrate. The NR networks were selectively grown in channel layer between the source and drain electrodes. The NR networks can provide additional electrical conducting path. The experimental results reveal the channel conductance of ZnO NR networks transistors can be manipulated by changing the drain and gate voltages. However, the proposed devices are expected to have potential extensive applications in next-generation optoelectronic devices.

並列關鍵字

InGaZnO ； ZnO ； ZnO nanorod ； photodetector ； transistor.

參考文獻

[1] D.W.Merfeld, et al. 2004, “Influence of GaN Material Characteristics on Device Performance for Blue and Ultraviolet Light-Emitting Diodes”, Journal of Electronic Materials, Vol. 33, No. 11.

[2] Kewei Liu , et al. 2010, “ZnO-Based Ultraviolet Photodetectors” , Sensors , Vol. 10, pp. 8604-8634.

[3] Hitoshi Aoki, et al. 1996, “Dynamic Characterization of a-Si TFT-LCD Pixels” IEEE Transactions On Eelectron Devices, Vol. 43, No. 1, January.

[4] Youji INOUE, et al. 2005, “Organic Thin-Film Transistors with High Electron Mobility Based on Perfluoropentacene” , Journal of Applied Physics Vol. 44, No. 6A, pp. 3663–3668.

[6] Hideo Hosono, 2006, “Ionic amorphous oxide semiconductors: Material design, carrier transport, and device application” , Journal of Non-Crystalline Solids, Vol. 352, pp. 851-858 .