• 文献标题:   High-Mobility Epitaxial Graphene on Ge/Si(100) Substrates
  • 文献类型:   Article
  • 作  者:   APROJANZ J, ROSENZWEIG P, NGUYEN TTN, KARAKACHIAN H, KUSTER K, STARKE U, LUKOSIUS M, LIPPERT G, SINTERHAUF A, WENDEROTH M, ZAKHAROV AA, TEGENKAMP C
  • 作者关键词:   epitaxial graphene, charge carrier mobilitie, ge epilayer, si 100, leed, photoemission, stm, surface transport
  • 出版物名称:   ACS APPLIED MATERIALS INTERFACES
  • ISSN:   1944-8244 EI 1944-8252
  • 通讯作者地址:   Tech Univ Chemnitz
  • 被引频次:   0
  • DOI:   10.1021/acsami.0c10725
  • 出版年:   2020

▎ 摘  要

Graphene was shown to reveal intriguing properties of its relativistic two-dimensional electron gas; however, its implementation to microelectronic applications is missing to date. In this work, we present a comprehensive study of epitaxial graphene on technologically relevant and in a standard CMOS process achievable Ge(100) epilayers grown on Si(100) substrates. Crystalline graphene monolayer structures were grown by means of chemical vapor deposition (CVD). Using angle-resolved photoemission spectroscopy and in situ surface transport measurements, we demonstrate their metallic character both in momentum and real space. Despite numerous crystalline imperfections, e.g., grain boundaries and strong corrugation, as compared to epitaxial graphene on SiC(0001), charge carrier mobilities of 1 x 10(4) cm(2)/Vs were obtained at room temperature, which is a result of the quasi-charge neutrality within the graphene monolayers on germanium and not dependent on the presence of an interface oxide. The interface roughness due to the facet structure of the Ge(100) epilayer, formed during the CVD growth of graphene, can be reduced via subsequent in situ annealing up to 850 degrees C coming along with an increase in the mobility by 30%. The formation of a Ge(100)-(2 x 1) structure demonstrates the weak interaction and effective delamination of graphene from the Ge/Si(100) substrate.