金-氧化鎵單晶奈米線的合成研究與電阻式記憶體之應用

Synthesis of Single Crystal Gold-in-Ga2O3 Nanowires and Their Application in Resistive Switching Memory

許家瑋(Chia-Wei Hsu)

指導教授 ： 闕郁倫

國立清華大學/工學院/材料科學工程學系/博士(2013年)

https://doi.org/10.6843/NTHU.2013.00488

摘要

本論文主要研究主題為一維金-氧化鎵異質結構奈米線的合成、成長機制、統計模型與電阻轉換性質探討。藉由鎵金屬、金奈米觸媒顆粒及氧化矽基板於800 ℃與1 × 10-2托爾環境下，在三區真空爐管中合成出帶有雙晶結構的一維核殼狀及豆夾狀金-氧化鎵異質奈米線。此外，利用羅吉斯迴歸建立異質結構奈米線的比例與合成參數模型，結果指出較高的溫度與較大的觸媒顆粒可以得到較密的異質結構，其原因來自於上述參數導致了金-鎵合金不均勻的過飽和現象，有利於金進入氧化鎵殼層中。
最後，我們發現單根金-氧化鎵核殼狀奈米線具有雙極式電阻轉換現象，更重要的是，此奈米線展現了不受電極距離影響的穩定操作電壓，這是由於此奈米線擁有連續金線作為內建的傳導層。這項特性使得在單根奈米線上製作多個電阻轉換元件成為可能。此外，金-氧化鎵核殼狀奈米線的開關比(on/off ratio)超過1000倍。這些特性使得金-氧化鎵核殼狀奈米線擁有成為未來高密度記憶體元件的潛力。

關鍵字

金-氧化鎵奈米線 ； 電阻式記憶體 ； 核殼狀奈米線

並列摘要

This thesis is commitment on the fabrication, growth mechanism, statistical model and resistive switching characteristic of one-dimensional gold-in-Ga2O3 heterostructure nanowires. We have successfully fabricated gold continuous nanowire or discrete nanoparticles embedded with twin boundary in the Ga2O3 shell layer using gallium (Ga) as growth source with gold (Au) as catalyst. The growth temperature was 800 ℃ with a pressure of 1 × 10-2 torr in a three-zone vacuum furnace through Vapor-Liquid-Solid (VLS) growth mechanism. Using the generalized logit regression to model the relationship between fabrication parameters and ratios of the heterostructures, we find that the heterostructure nanowire density can be increased at higher temperature and larger catalyst size resulted from non-uniform supersaturation between edge side and center area of Au-Ga droplet.
Finally, we investigated the resistive switching behaviors of single gold-in-Ga2O3 core-shell nanowire, for which the bipolar resistive switching characteristics with invariable set and reset voltages can be obtained. We attribute the unique property of invariance to the built-in conduction paths of gold core. This invariance allows us to fabricate many resistive switching cells with the same operating voltage by depositing repetitive metal electrodes along a single nanowire. Other characteristics of these core-shell resistive switching nanowires include comparable driving electric field with other thin film and a remarkable on/off ratio more than 3 orders of magnitude at a low driving voltage of 2 V. A smaller but still impressive on/off ratio of 10 can be obtained at an even lower bias of 0.2 V. These characteristics of gold-in-Ga2O3 core-shell nanowires make it a viable candidate for future high-density resistive memory devices.

並列關鍵字

Gold-in-Ga2O3 Nanowires ； Resistive Switching Memory ； Core-Shell Nanowires

參考文獻

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