新穎半導體奈米結構合成與成長動力學及其晶體結構與性質研究

Abstract

近幾年的先進奈米科技提供了延續摩爾定律在預測半導體元件在超大型積體電路中 持續微型化的希望，而以矽、鍺、三五族材料為基礎的奈米結構在未來的電腦與半導 體科技扮演著很重要的角色。在此計晝中，我提出探討四族與三五族材料為基礎的奈 米結構形成，並利用穿透式電子顯微鏡對不同奈米結構做臨場動力學研究與非臨場晶 體結構和化學的研究。臨場穿透式電子顯微鏡提供了材料在高溫時反應的觀察，進一 步我們可以研究成長動力學與模型。以矽化物在奈米線中的行長為例，我們可以利用 穿透式電子顯微鏡的臨場觀察來精確的控制奈米級距的異質結構，也就是兩段矽化物 之間只間隔了幾個原子層距離的矽。同時，原子等級的成長過程也可以直接被觀察與 紀錄。此外，本計晝也將進一步研究一維奈米線週期性排列的試片製作，成長各式奈 米結構，並控制其奈米線間的距離。此種樣品，在動力學研究之外，同時也可被評估 為未來的可能的應用奈米元件。利用交通大學電子物理系的國科的貴重儀器設備，球 面像差校正穿透式電子顯微鏡，並配合基本製程設備，此計晝將也會著重於在奈米材 料與結構的介面分析、能量分析、化學分析。此外，利用金屬矽化物在一維奈米元件 的重要性，我們進一步將其利用在我們成長的奈米結構與奈米異質結構，並研究其矽 化過程與其成核成長動力學，並提供日後電性量測的接觸媒介。

Recent advances in nanotechnology have offered hope of extending Moore’s law of large scale integration of semiconductor device circuits to nanodevices. Nanostructures based on Si, Ge and III-V will play an important role in future computer technology. In this proposal, I propose to explore the formation of nanostructures based on group IV and III-V materials and use transmission electron microscopy for in situ studies of solid-state chemical reactions in such nanostructures and for ex situ studies for the crystallography and chemistry of the nanostructures. In situ TEM imaging allows the reaction to be followed in real time in atomic resolution and the modeling of the growth kinetics. It is possible to control the formation of the metal silicide accurately enough to fabricate nano-gap heterostructures, where silicide regions are separated by just a few atomic planes of Si. The atomic-level details of the growth process will be examined directly. Besides, I will make efforts on the fabrication of nanowire-based crossbar samples with designed length and distance for further kinetic study and evaluation of future applications. The Cs-corrected TEM located in Dept. of Electrophysics in NCTU under NSC user facility will be used for materials characterization including strain analysis and sharpness of interface by the analytical capability of the microscope. Furthermore, transition metal silicide nanowires are considered strong candidates for circuit elements in one-dimensional nanodevices, with applications including ohmic contacts, Schottky barriers, gate electrodes and interconnects. I propose to form silicide with controlled phases in the nanostructures grown in the lab and study silicidation mechanisms in such nanostructures as well as opens up a route for electrical measurement by silicide contacts.