鍺對奈米線pH-靈敏度的影響

Abstract

近年來，由於元件的微縮，使得奈米線和奈米結構變得相當的熱門。奈米線主要被拿來應用於生物感測器或奈米電子元件，因和傳統元件相比，其具有較快速的元件轉換速度和低功率消耗之優點。奈米線的側壁相當的敏感，可用來偵測相當細微的變化。 在這篇研究中，我們引入了矽鍺的應用，來製作出矽鍺奈米線，利用鍺有比較高的遷移率，故將其以不同比例的鍺摻入矽中，而所成長出的矽鍺層，會隨著鍺的濃度增加，使我們的元件具有較高的靈敏度。首先我們將製作好的奈米線滴上APTES做表面處理，接著滴上我們要測量的pH液。藉由分析pH5、pH9、pH11的改變量我們可以發現奈米線的靈敏度隨著鍺濃度的增加而增加。但在更高濃度40%鍺時，其靈敏度低於30%鍺。我們猜測可能的原因為太高濃度的鍺會造成更多的表面缺陷。

Due to the scaling down of devices, nanowire and nanostructure attracts many interests recently. Nanowire is mainly used in biological sensor or nanoelectronics, because it has the advantages of faster switching speeds and lower power consumption than conventional devices. The sidewall of nanowire is very sensitive and this could be used to detect the slight variation of the condition. In this thesis, we have successfully fabricated the N-SiGe and P-SiGe nanowire with different Ge concentration respectively. The 3-aminopropy- ltriethoxysilane (APTES) was used to modify the surface, which can detect the charge with different pH solution. The percentage change of conductivity among pH5, pH9 and pH11 is calculated to confirm the improvement of SiGe nanowire with different Ge concentration. But our experiment found the higher Ge concentration (40%) has not increased the sensitivity; the reason maybe the higher defect appears at the surface as higher Ge concentration.