March 19, 2012 — University of Texas at Austin researchers demonstrated high-quality, wafer-scale graphene deposition on evaporated copper films, using an AIXTRON cold-wall vertical BM (Black Magic) Pro reactor. The BM Pro is a high-performance, flexible chemical vapor deposition (CVD) processing platform with high uniformity.
Using a lower processing temperature than that needed for graphene synthesis on copper foil, the researchers deposited monolayer graphene chemical with negligible defects onto evaporated copper films on the wafer-scale.
"A pre-annealing process is used at first to create a hydrogen-rich polycrystalline copper film of <111> preferential orientation, followed by the decomposition of pure methane for the growth of high quality graphene. The growth proceeds without the need for hydrogen gas during the growth phase, and occurs at a lower processing temperature than on copper foil," said Prof. Deji Akinwande, who led this research together with Prof. Rod Ruoff’s team at the Microelectronics Research Center at UT Austin.
Wafer-scale graphene synthesis with negligible defects is essential for heterogeneous graphene/silicon VLSI applications and industrial adoption of graphene, said Professor Akinwande.
The experimental work was carried out at the National Nanotechnology Infrastructure Network (NNIN) and Texas Materials Institute (TMI) facilities at The University of Texas at Austin, supported in part by the Nanoelectronic Research Initiative (NRI-SWAN Center), and the Office of Naval Research.
The Microelectronics Research Center is equipped with state-of-the-art semiconductor fabrication equipment in 12,000sq.ft. of Class 100 and Class 1000 cleanroom space, with 15,000sq.ft. characterization laboratories. The Center has 15 faculty and 120 graduate students.
|Shown standing beside the AIXTRON BM Pro PECVD reactor (L to R): Li Tao (postdoc scholar), Nassibe Rahimi, Kristen Parrish, Maryam Mortazavi and Fahad Chowdhury (all PhD students).|
Results are published by ACS Nano: Li Tao, Jongho Lee, Harry Chou, Milo Holt, Rodney S. Ruoff, and Prof. Deji Akinwande, "Synthesis of High Quality Monolayer Graphene at Reduced Temperature on Hydrogen-Enriched Evaporated Copper (111) Films," ACS Nano (2012), DOI: 10.1021/nn205068n.