[F-1-2] Formation of Trench Pattern on Ge Surface by Enhanced Chemical Etching Using Chemically Modified Graphene Flakes 〇Ryo Mikurino1, Ayumi Ogasawara1, Tomoki Hirano1, Kentaro Kawai1, Kazuya Yamamura1, Kenta Arima1 (1.Osaka University) Keywords:Surface treatment、graphene surface、trench formation、dissolved oxygen、