Formation of graphene on diamond C(111) surfaces by vacuum annealing

真空加熱処理によるダイヤモンドC(111)表面でのグラフェン形成

小川 修一*; 山田 貴壽*; 石塚 眞治*; 吉越 章隆 ; 加賀 利瑛*; 穂積 英彬*; 長谷川 雅考*; 寺岡 有殿; 高桑 雄二*

Ogawa, Shuichi*; Yamada, Takatoshi*; Ishizuka, Shinji*; Yoshigoe, Akitaka; Kaga, Toshiteru*; Hozumi, Hideaki*; Hasegawa, Masataka*; Teraoka, Yuden; Takakuwa, Yuji*

Graphene on diamond (GOD) structures have been attracted much attention as a substrate for the high-speed and high-power semiconductor devices. By using a diamond(111) surface, the epitaxial growth of graphene can be expected. It has been reported that the graphitization of the diamond(111) surfaces by annealing in vacuum, but the detail process has not been clarified yet. The aim of this study is to identify the sp-bonded carbon layer and to clarify the graphene formation mechanism on the diamond(111) surface. In order to achieve the aim, real-time photoemission spectroscopy using synchrotron radiation was employed for investigation of the vacuum annealing process of the hydrogen-terminated diamond(111) surface. It was found that sp-bonded amorphous carbon layer generated at about 1073 K. By further annealing above 1223 K, the amorphous sp carbons graphitize, leading to the graphene formation on the diamond C(111) surfaces.