低溫成長高載子遷移率與低接觸電阻之石墨烯

Abstract

在本論文中，研究主題可分為兩部分。第一部分為探討利用低溫電漿輔助化學氣相沉積法來成長石墨烯，並深入分析如何選擇各個實驗參數，直到最後能夠成功地成長出品質優良的石墨烯薄膜。而成長出的石墨烯薄膜再利用光學顯微鏡、掃描式電子顯微鏡以及拉曼光譜儀來檢測其品質。接著再將此石墨烯薄膜分別轉印到二氧化矽基板與ODTS基板上，並製作成石墨烯場效電晶體元件，量測其載子遷移率。再與利用商業用石墨烯製作的石墨烯場效電晶體元件做比較，來證明本實驗所成長的石墨烯薄膜可以達到很高的載子遷移率。 第二部分則是利用本實驗成長之石墨烯製作成TLM(Transfer Length Method)元件，來量測其與金屬電極間的接觸電阻，而本實驗中所選用的金屬電極為銀與金。而在得到實驗結果之後，將會利用XPS與UPS來探討石墨烯與金屬之間的交互作用對接觸電阻的影響。接著再將此實驗結果與利用高溫化學氣相沉積法所成長的石墨烯製作的TLM元件做比較，以此證明本實驗成長之石墨烯和銀與金之間具有很小的接觸電阻。最後則是討論低溫製程石墨烯的品質能過超越高溫製程石墨烯的原因，以及其更深入的應用。

In this thesis, the topic can be divided into two parts. In the first part, we discuss how to use low temperature Plasma Enhanced Chemical Vapor Deposition to fabricate graphene. We analyze thoroughly how we adjust each parameter, until we can successfully fabricate graphene with good quality. After the graphene is fabricated, we use Optical Microscope, Scanning Electronic Microscope and Raman spectrum to examine the quality of this graphene film, to ensure its high quality. Next, we transfer this graphene onto Silicon Dioxide substrate and ODTS substrate to fabricate Graphene Field Effect Transistor(GFET), in order to extract the carrier mobility of the graphene. And we compare the result with the commercial-graphene made GFET, to prove that our graphene indeed has high carrier mobility. In the second part, we use Transfer Length Method(TLM) to examine the contact resistance between this graphene and metal electrode, Ag and Au. After we get the result, we analyze the interaction between graphene and metal by X-ray Photoelectron Spectroscopy and Ultraviolet Photoelectron Spectroscopy. Then we compare our contact resistance with the result from High Temperature Chemical Vapor Deposition graphene, to prove that our graphene indeed again, has lower contact resistance with Ag and Au. At last, we discuss the reason why our low temperature deposition process can have such great quality compare with the high temperature deposition, and its further application.