矽基與鎳矽化物奈米材料之合成與鑑定

Synthesis and Characterization of Si-Based and Nickel Silicide Nanostructures

吳漢威(Han-Wei Wu)

指導教授 ： 陳力俊 ； 蔡哲正

國立清華大學/工學院/材料科學工程學系/博士(2007年)

摘要

奈米結構常常有別於塊材的本身特質而有獨特的物理性質，引發廣泛的興趣和研究。本論文以合成新穎奈米材料為主題，並且對這些合成出來的奈米材料進行結構分析鑑定與成長機制探討，同時對其奈米材料獨特的性質做進一步的研究與設計運用。
利用聚苯乙烯奈米球微影方法控制金催化劑密度的方法在矽基板上合成出自組裝的磊晶一維矽奈米線並討論此獨特奈米線的成長機制。此外，在傳統半導體材料中摻雜少量磁性元素，形成所謂稀磁半導體(DMS)可運用在自旋電子元件上。利用離子佈植的方法製作出具有常溫鐵磁性的一維錳離子摻雜之矽奈米線。證實了適當條件的退火以及錳摻雜量有助於提升矽奈米線的鐵磁性，提高作為自旋電子元件的可能性。
金屬性質矽化物因為具有高熔點、良好熱穩定性及低電阻優點，故在VLSI半導體製程應用上有舉足輕重的地位。本研究利用簡單的化學氣相反應的方式，嘗試在矽基板上生成獨立生長的鎳矽化物奈米結構。由實驗結果顯示反應物的蒸氣量會影響到奈米結構的外觀，而對於金屬矽化物的電性量測以及結構分析亦為本論文之重點。另外，我們並利用模擬軟體去檢測出不同寬度奈米帶之厚度，此方法有助於我們對奈米帶電性量測的瞭解。
利用規則排列的聚苯乙烯球以及硝酸鎵溶液合成出三維規則的多孔氧化鎵奈米結構，並進行結構分析與與氣體感測。由實驗結果顯示此大表面積比的三維半導體結構材料能有效提升偵測二氧化氮氣體的敏感度。由於此合成方法可以簡單的製作出金屬、半導體以及金屬氧化物等不同種類的材料，使得他們有很大的潛力運用在氣體感測、光子晶體以及光電元件運用上。

關鍵字

奈米線 ； 矽 ； 鎳矽化物 ； 氧化鎵

並列摘要

Self-assembled epitaxial silicon nanowires on the surface of Si(001) have been grown and discuss on how the effect of density and size of Au nanodot catalysts for these nanowires can influence their growth. The possible growth mechanism is discussed in detail based on the VLS for self-assembled epitaxial silicon nanowires. In addition, we fabricate room temperature ferromagnetism of Mn+-implanted Si nanowires by ion implantation. The saturation magnetization was found to increase with the Mn concentration. Appropriate annealing condition can heal the displacement damage and increase the saturation magnetization in the Mn+-implanted Si nanowires.
Single-crystal Ni2Si, Ni3Si2, Ni31Si12, and Ni3Si nanostructures including nanobranches, nanowires and nanobelts were synthesized by a chemical vapor deposition (CVD) method. The experimental observation suggests that vapor pressure of the nickel precursor was critically important in the morphology of silicide NWs. The studies for these silicide nanostructures mainly focus on synthesis, structure characterization, and electrical measurements. In addition, using the method of comparison of the experimental high-resolution TEM images with the simulated images, the thickness of nanobelts could be determined.
Large-area ordered porous Ga2O3 films on silicon substrates were grown based on colloidal template and direct solution dipping methods. The structure has a high specific surface area to enhance the sensitivity of Ga2O3 in detecting NO2 at 200 oC. The thickness and morphologies of the samples can be controlled by the solution concentration. The results show great potential of these ordered nano-materials in sensing, photonic and optoelectronic applications.

並列關鍵字

Nanowires ； Silicon ； Nickel Silicide ； Ga2O3

參考文獻

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