此研究工作主要在探討高溫超導體釔鋇銅氧約瑟芬接面及超導量子干涉元件之製作與特性。為了製作出階梯式界面基座，我們研發出一精緻的蝕刻製程，並藉此製程製作出高品質的階梯式界面基座。利用此高品質的階梯式界面基座，我們進一步出製作釔鋇銅氧約瑟芬接面及超導量子干涉元件。經由量測釔鋇銅氧約瑟芬接面的特性後發現，其電壓-電流曲線呈現出電阻性分流接面的特性，並且此曲線對外加微波有著強烈的反應。在高溫時，熱能對約瑟芬耦合會產生明顯的擾動而減低耦合強度。藉由接面的臨界電流與溫度的關係發現，此種階梯式釔鋇銅氧約瑟芬接面具有超導體-絕緣層-超導體結構接面的特質。進一步的研究指出，在界面中的雜質對接面的傳輸特性有著非常重要的影響。在此論文中，我們亦研究造成釔鋇銅氧約瑟芬接面電壓雜訊的原因。結果發現，接面臨界電流的漲落是造成低頻電壓雜訊的主要源由。在釔鋇銅氧超導量子干涉元件特性研究方面，我們可清楚的觀察到超導量子干涉現象。在高溫時，由於熱擾亂的關係，當通一非常小的電流於超導量子干涉元件時，亦可觀察到超導量子干涉現象。藉由對超導量子干涉元件磁通雜訊的量測發現，接面臨界電流的漲落及在元件內磁通的運動是造成低頻磁通雜訊的原因。

In this work, the fabrication and the characterizations of the high-Tc YBa2Cu3Oy (YBCO) Josephson junctions and superconducting quantum interference devices (SQUIDs) are investigated. To obtain the step-edge MgO substrates for the high-Tc Joseohson junctions and SQUIDs, an etching process is developed and refined to achieve the high-quality step-edge substrates. The morphology of the step edge examined by using atomic force microscope reveals a highly homogeneity in the step height and step angle along the step-edge line. With the step-edge MgO substrates, the YBCO Josephson junctions and SQUIDs are fabricated. The V-I curves of the step-edge YBCO Josephson junctions exhibit the RSJ behavior, and the microwave response of the V-I curves is observed clearly. The disruption of the Josephon coupling by the thermal fluctuations was found to play an important role when the junctions were operated at higher temperatures. The experimental temperature dependence of the critical current of the step-edge YBCO Josephson junction displays the SIS-like behavior. Further studies indicated that the localized states caused by the defects at the grain boundaries are dominant to the transport behavior and account for the scaling low of IcRn  Jcp with p around 0.5. The origins of the voltage noises of the step-edge YBCO Josephson junctions are also clarified in this report. It was found that the critical current fluctuations dominate the low-frequency 1/f voltage noises. The superconducting quantum interference effects, such as the V-phiand Ic-phi curves, were observed for the step-edge YBCO SQUIDs. At higher temperatures, the thermal effects become significant, and hence a V-phi curve can be found for the step-edge YBCO SQUIDs biased with a current close to zero. By measuring the flux noises of the YBCO SQUID, it was found that both the critical current fluctuations and flux motion can induce the 1/f flux noises.

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