溶液製程製作氧化物半導體與電晶體之研究

Studies of Solution-Processed Oxide Semiconductors and Thin Film Transistors

陳昶亙(Chang-Ken Chen)

指導教授 ： 吳忠幟

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2008年)

https://doi.org/10.6342/NTU.2008.10383

摘要

近年來，氧化物半導體做為薄膜電晶體通道層應用的出現，引起廣泛的研究與注目。氧化物半導體以金屬陽離子外層球狀軌域形成導帶結構，無論在結晶或非晶結構下都能維持相當的載子傳輸能力。同時氧化物半導體為寬能隙(wide bandgap)材料，具有在可見光波段為透明的特性，可有效增加顯示器之開口率，甚至以此製作透明電路。目前製作氧化物薄膜電晶體大多以真空製程做為沉積氧化物半導體的方式，包括：射頻-磁控濺鍍(RF magnetron sputter)、脈衝雷射蒸鍍(pulse laser deposition, PLD)以及熱蒸鍍等需要真空腔體的成膜方式，因此需要較為昂貴的成膜設備。溶液製程提供一個簡單、低成本且適用於一般大氣環境製程的薄膜沉積方式，同時藉由變化溶液原料的成分組合比例，能夠簡便地調整氧化物薄膜的物理、化學以及光學特性以達到不同的需求。
本論文中，以金屬氯化物(metal chloride)做為前驅物原料，以旋轉塗佈(spin coating)方式製備單一及多元氧化物薄膜。藉由觀察前驅物溶液的熱重變化，及氧化物薄膜的表面型態，分析薄膜的成膜機制與結晶特性，證實本研究中製備之氧化物薄膜多為平坦連續之非晶態薄膜。同時由光學穿透頻譜也證實製備之薄膜在可見光區具有90﹪以上之穿透率。
　　在氧化物薄膜電晶體特性方面，本論文有效以溶液製程製作多種不同金屬氧化物成分之薄膜電晶體元件，同時分析不同薄膜厚度、金屬氧化物成分比例及熱處理溫度等條件下電晶體特性的差異，並針對導致其元件特性差異的物理機制進行探討。

關鍵字

氧化物半導體 ； 薄膜電晶體 ； 溶液製程 ； 金屬氯化物 ； 氧化鋅錫

並列摘要

Oxide semiconductors for application in thin film transistors (TFTs) have drawn much attention in recent years. Oxide-based Semiconductors composed of heavy metal cations with spherical ns orbital to form conduction bands have various merits. First of all, high carrier transport properties (mobility) can be achieved in both crystalline and amorphous phase. Besides, the bandgap of oxide semiconductors is usually large and thus they are transparent in the visible range, which could be used to improves the aperture ratio of flat panel displays, or probably could be used for transparent electronics. Most oxide-semiconductor-based TFTs reported were fabricated by vacuum deposition techniques, such as pulsed laser deposition (PLD), RF magnetron sputtering deposition, and thermal evaporation, and thus are rather high cost. Solution-based oxide semiconductor deposition process is likely an alternative to achieve low-cost manufacturing and enable large-area deposition. Furthermore, solution processes also provide a convenient way to adjust the electrical, optical, and physical properties by simply modify compositions of precursors.
In this thesis, we deposited single and multi-components oxide semiconductor thin films by solution process. Metal chloride precursor solutions for fabricating oxide thin films were deposited on substrate by spin-coating method under ambient condition. The reactions of precursors were analyzed according to the thermogravimetric variation of precursors. Furthermore, the morphology of thin films was measured to verify the crystalline or amorphous characteristics of films. Also, the UV-Vis measurement indicates the transparency up to 90﹪for all these oxide thin films.
As for the oxide-based thin film transistors, functional thin film transistors based on solution-processed were effectively fabricated. The influences of film thickness, ratios of metal cations and annealing temperatures are investigated.

並列關鍵字

oxide semiconductors ； thin film transistors ； solution-processed ； metal chloride ； zinc tin oxide

參考文獻

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