以低溫水溶液製程進行氧化鋅薄膜側向磊晶成長之研究

The Study of Lateral Epitaxial Overgrowth of ZnO Thin Films in Aqueous Solution

余明陽(Ming-Yang Yu)

指導教授 ： 陳厚光

義守大學/理工學院/材料科學與工程學系/碩士(2014年)

https://doi.org/10.6343/ISU.2014.00164

摘要

本研究於水溶液中進行氧化鋅薄膜側向磊晶成長。本論文中主要分為兩部分，第一部分先在藍寶石基板上成長準直磊晶氧化鋅柱，再以高分子(G1 epoxy、聚二甲基矽氧烷)轉移氧化鋅磊晶柱，獲得ZnO/高分子複合材。由於氧化鋅晶柱在高分子基地仍保有高度in-plane方位關係，再以此關係於水溶液中添加檸檬酸鈉進行側向成長磊晶氧化鋅薄膜，達到在高分子複合材上生長二維平面高方向薄膜之目的。
第二部分主要以擇區成長機制搭配lift-off製程分別在藍寶石基板製作線狀及點狀圖案化ZnAl2O4緩衝層。並分別利用兩種圖案緩衝層，進行側向磊晶成長。在側向磊晶成長方面，將嘗試在水溶液中分別加入檸檬酸鈉及氯化鉀作為ZnO (0001)面成長抑制劑，比較不同抑制劑對於側向成長影響。當晶體從緩衝層生長後逐漸往側翼(wing)成長，而側向生長機制較接近同質磊晶，原在window區域的差排也較難往側翼移動。癒合成連續薄膜根據SEM及TEM觀察，window的差排缺陷數量遠比側翼生長區多。

關鍵字

氧化鋅側向磊晶 ； 高分子復合材 ； 電子顯微鏡 ； 水熱法

並列摘要

In this study, lateral epitaxial overgrowth of ZnO films were implemented in low temperature aqueous solution. The thesis can be divided into two parts: (1) ZnO microrods/polymer composites promote biaxially oriented growth of ZnO films on glass substrates; (2) patterned buffer layer assisted lateral epitaxial overgrowth (LEO) of ZnO films.
For preparation of ZnO microrods/polymer composite, we infiltrated polydimethylsiloxane (PDMS) and G1 epoxy into epitaxial ZnO microrod arrays on sapphire substrates, respectively. After curing, the resulting ZnO/polymer composite layers were transferred to glass substrates by peel-off processing. The ZnO microrods embedded in the polymer matrix exhibited their well-defined in-plane alignment. The hydrothermal growth of ZnO were performed on the opposite face of ZnO microrods/polymer composite by immersing it in growth solution containing zinc nitrate, hexamethylenetetramine, and sodium citrate. [0001]-oriented ZnO posts with biaxial alignment can be grown on the composite templates. Due to addition of sodium citrate into growth solution, biaxially oriented ZnO films with a continuous and flat morphology can be obtained through coalescence overgrowth of the ZnO posts.
For patterned buffer layer assisted lateral epitaxial overgrowth of ZnO films, patterned epitaxial ZnAl2O4 buffer layers were fabricated by combining lift-off and solid state reaction processing. Two types of masks were used to fabricate stripe windows and hexagonal arrays of circular windows. Hydrothermal epitaxial growth of ZnO grains only occur on the regions where the lattice matched ZnAl2O4 buffer layers were covered. Such selected area growth mechanism promotes lateral epitaxial overgrowth of ZnO films on the sapphire substrates without mask layer assistance. For lateral epitaxial overgrowth of ZnO, we added sodium citrate and KCl into growth solution, respectively, to inhibit the growth in ont-of-plane directions, e.g. [0001], and promote growth in lateral direction. The microstructures corresponding to window and wing regions were systematically investigated by SEM observation and TEM analysis. Also, the optical properties of the LEO ZnO films were studied by photoluminescence.

並列關鍵字

ZnO lateral epitaxial Overgrowth ； polymer composite material ； Electron microscopy ； hydrothermal

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