title: Transfer-free batch fabrication of large-area suspended graphene membranes.
abstract: We demonstrate a process for batch production of large-area (100-3000 microm(2)) patterned free-standing graphene membranes on Cu scaffolds using chemical vapor deposition (CVD)-grown graphene. This technique avoids the use of silicon and transfers of graphene. As one application of this technique, we fabricate transmission electron microscopy (TEM) sample supports. TEM characterization of the graphene membranes reveals relatively clean, highly TEM-transparent, single-layer graphene regions ( approximately 50% by area) and, despite the polycrystalline nature of CVD graphene, membrane yields as high as 75-100%. This high yield verifies that the intrinsic strength and integrity of CVD-grown graphene films is sufficient for sub-100 microm width membrane applications. Elemental analysis (electron energy loss spectroscopy (EELS) and X-ray energy-dispersive spectroscopy (EDS)) of the graphene membranes reveals some nanoscaled contamination left over from the etching process, and we suggest several ways to reduce this contamination and improve the quality of the graphene for electronic device applications. This large-scale production of suspended graphene membranes facilitates access to the two-dimensional physics of graphene that are suppressed by substrate interactions and enables the widespread use of graphene-based sample supports for electron and optical microscopy.
authors.affiliation: Department of Physics, University of California at Berkeley, California 94720, USA.
authors.forename: Benjamín
authors.initials: B
authors.lastname: Alemán
authors.forename: William
authors.initials: W
authors.lastname: Regan
authors.forename: Shaul
authors.initials: S
authors.lastname: Aloni
authors.forename: Virginia
authors.initials: V
authors.lastname: Altoe
authors.forename: Nasim
authors.initials: N
authors.lastname: Alem
authors.forename: Caglar
authors.initials: C
authors.lastname: Girit
authors.forename: Baisong
authors.initials: B
authors.lastname: Geng
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Maserati
authors.forename: Michael
authors.initials: M
authors.lastname: Crommie
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: A
authors.initials: A
authors.lastname: Zettl
mesh_terms: D002244:Carbon / Q000737:chemistry*; D003300:Copper / Q000737:chemistry; D008567:Membranes, Artificial; D046529:Microscopy, Electron, Transmission; D036103:Nanotechnology / Q000191:economics / Q000379:methods*; D055620:Optical Phenomena; D013499:Surface Properties; D013535:Suspensions; D014835:Volatilization
chemical_list: D008567:Membranes, Artificial; D013535:Suspensions; D002244:Carbon; D003300:Copper