單晶二氧化釕奈米線之低頻雜訊研究

Abstract

隨著現今奈米科技的發展，由於電子元件的微小化，對於俱備良好導電度、熱穩定性與化學穩定性的奈米導線需求是日益增進，量子力學的修正更是一個重要的研究重點，如量子相位干涉、普適電導漲落…等。低頻雜訊廣泛地存在於大自然中，是一種功頻譜密度與頻率、元件尺度成反比的一種訊號，隨著元件的微小化，導致低頻雜訊對於電子傳輸影響甚大，相當具有研究價值，由於其可以對於移動缺陷俱有相當高的靈敏度，對於原子級移動缺陷數目的觀察也可被運用於其他領域。 本篇論文以電子束微影製程製作鉻金電極，透過四點量測以及利用交流電量測法避免非樣品本身所造成的雜訊擾動，研究過渡元素氧化物－單晶二氧化釕奈米線常溫到低溫的低頻雜訊，以二能級系統在常溫的熱活化能效應解釋功頻譜密度隨溫度下降，到低溫導致功頻譜密度隨著溫度下降而上升的缺陷量子穿隧與隨時變普適電導漲落。 雖然解釋低頻雜訊的理論沒有統一，但由於二氧化釕奈米線的載子數目相當多，所以本論文不以載子數目的擾動來解釋，而是以缺陷的擾動導致遷移率的改變來解釋低頻雜訊擾動的現象。

With the development of modern nanotechnology, since miniaturization of electronic devices, ready for low resistivity, excellent thermal and chemical stability nanowires demand is becoming the promotion. Correction of quantum mechanics is an important research focus, such as quantum phase interference, universal conductance fluctuations ... and so on. Low-frequency noise exists widely in nature, a signal that power spectral density is inversely proportional to the frequency and sample size. With the miniaturization of components, resulting in low frequency noise for the electronic transmission of great influence, therefore consider research value. Because the noise has high sensitivity to the existence of mobile defect, it can be applied to other areas. In this thesis, Cr/Au electrodes were patterned onto the nanowires using the electron-beam lithography. The four-point measurement and the ac techniques are applied to avoid noise caused by non-sample itself. Study the transition element oxides – single crystalline ruthenium dioxide nanowires at room temperature to low temperature of the low-frequency noise. In two-level systems (TLSs), the thermal activation effect at high temperature explanation power spectral density decreases with decreasing temperature. The quantum tunneling and time dependent universal conductance fluctuations (TDUCFs) effect at law temperature explanation PSD increases with decreasing temperature. There are many theories to explain the low-frequency noise. Because there are a large number of carriers in this RuO2 nanowires, the carrier mobility fluctuation to explain low frequency noise in this thesis instead of the carrier number fluctuation.