錳矽化物奈米線異質結構及其電子傳輸特性研究

Abstract

金屬矽化物奈米線具有許多獨特的物理特性，因此近年來引起眾多學者們的興趣與研究，在這些矽化物中，錳矽化物的奈米結構更因為其廣泛的應用性，例如微電子、光電、自旋電子學以及熱電裝置等，而受到極大的注意。 本研究經由固態反應，透過線接觸的方式，成功地使錳電極和矽奈米線反應形成矽化錳奈米線及矽化錳奈米線之異質結構，同時藉由臨場穿透式電子顯微鏡觀察錳矽化物奈米線生成的過程，並計算成長速率，利用球面像差修正掃描穿透式電子顯微鏡來進行其成分分析與結構鑑定，觀察到立方晶系之MnSi。在引入外層氧化鋁的影響後，得到相當平整之矽化錳與矽奈米線異質界面，且發現殼層氧化鋁不僅會改變反應的擴散行為，更可促進單晶之成長，幫助磊晶關係的維持，此外，本研究還會針對矽化錳奈米線及矽化錳/矽/矽化錳奈米線異質結構進行電子傳輸特性的量測與分析。本研究成果，預期將對未來的奈米製程科技及相關應用帶來重要的參考價值與影響。

Metal silicide nanowires (NWs) are of great interesting materials with diverse physical properties. Among these silicides, manganese silicides nanostructures have been attracted wide attention due to their several potential applications, including microelectronics, optoelectronics, spintronics and thermoelectric devices. In this work, we exhibited the formation of pure manganese silicide and manganese silicide/silicon nanowire heterostructures through solid state reaction with line contacts between manganese pads and silicon NWs. The growth process, structure and composition analysis of manganese silicide NWs have been investigated by in-situ transmission electron microscopy (in-situ -TEM) and spherical aberration corrected scanning transmission electron microscope (Cs-corrected STEM), respectively. The growth rates and the formation of manganese silicide phase under thermal effect were systematically studied. Additionally, we added Al2O3 as the surface oxide on the growth of MnSi nanowire. We find that oxide-shell not only enhance the silicide/Si epitaxial growth but also effect the diffusion process in silicon nanowire. Furthermore, we have investigated the electron transport properties of the Mn silicide/silicon/Mn silicide nanowire heterostructures based devices. In addition to fundamental science, the significant study would be helpful for future processing techniques in nanotechnology and related applications.