Graphene growth on ultraflat SiC surfaces assisted by preferential etching of surface Si atoms

2014 Fiscal Year Final Research Report

• Project/Area Number: 24656101
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Production engineering/Processing studies
• Research Institution: Osaka University
• Principal Investigator: ARIMA KENTA 大阪大学, 工学(系)研究科(研究院), 准教授 (10324807)
• Co-Investigator(Renkei-kenkyūsha): SANO Yasuhisa 大阪大学, 大学院工学研究科, 准教授 (40252598)
• Research Collaborator: SAITO Naoki ; MORI Daichi
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: グラフェン / シリコンカーバイド / プラズマ処理 / ウェットエッチング / 超平坦表面

Outline of Final Research Achievements

Epitaxial graphene on silicon carbide (SiC) is obtained easily by heating a Si-face SiC(0001) surface in ultrahigh vacuum. However, this process produces a SiC surface with a pitted morphology, which degrades the quality of graphene on it.
The pitted morphology originates from the rapid and random sublimation of Si from the terraces that are not covered by a buffer layer. Thus, a strategy to yield pit-free graphene is to form a homogeneous buffer layer on the entire SiC surface. We present a novel technique to form a carbon overlayer at the monolayer scale on an atomically flattened SiC(0001) Si-face substrate involving plasma oxidation at atmospheric pressure followed by HF etching, both of which are performed at near room temperature. We subsequently anneal the SiC surface with additional carbon atoms in vacuum to grow graphene. Its surface morphology exhibits few pits on terraces with widths of approximately 500 nm, in strong contrast to graphene grown on an initial SiC surface.

Free Research Field

半導体表面科学