矽鍺奈米線的製作和電性探討

Abstract

近年來，由於元件的微縮，使得nanowire和nanostructure變得相當的熱門。Nanowire主要被拿來應用於biological sensor或nanoelectronics，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。Nanowire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SiGe的應用，來製作出SiGe nanowire，利用Ge有比較高的mobility，故將其以不同比例的摻入Si中，而所成長出的SiGe層，會隨著Ge的濃度增加，使我們的元件具有較高的電流傳導力。起先我們先用濕氧化製程長氧化層，再用TEL 5000乾式蝕刻機台把氧化層蝕刻成一個個階梯狀。利用UHV-CVD機台來成長SiGe，將其疊在oxide step上，再利用TCP 9400乾式蝕刻機台把所疊的SiGe film蝕刻掉，則SiGe nanowire會被精巧的製作在剩餘的spacer上。之後欲得到更大的電流，我們再將Source/Drain打入離子佈植，由於降低了Al/SiGe之間的接觸電阻，使電流加大的提高。之後再整個nanowire都打入離子佈植，由於在通道中提供了更多的導通載子，以致於電流更大大的被提升，更加的利於我們日後拿來做為sensor方面的應用。

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 involve the application of SiGe to fabricate SiGe nanowire. Ulitize the higher mobility of Ge, and formed different SiGe alloy concentration. The grown SiGe layer will enhance current with the Ge content increases. First, we oxidized the Si bulk by wet oxidation. By lithography, we fabricated each step of the oxide. An then, We deposited SiGe layer on the oxide step by Ultra High Vaccum-Chemical Vapor Deposition (UHV-CVD), and then etched the SiGe film. The SiGe nanowire will elaborately formed in the side-wall spacer. Later we treated the Source/Drain with ion implanation to get the higher current due to the reduction the Al/SiGe contact resistance. The current was more improved by implanted the channel. It favored the application for the nanowire to be a sensor later.