Local growth of graphene on Cu and Cu0.88Ni0.12 foil substrates

Abstract

A method for large single-grain graphene growth on a Cu0.88Ni0.12-alloy using a local precursor feeding setup has been reported. Using back-end of line integration devices exploiting the high mobility and good mechanical properties can be built. However, few details about the actual local feeding setup and the yield are known. A local precursor feeding setup was implemented using a conventional tube-furnace, modified to allow local precursor feeding. Ar-diluted CH4 as the C precursor was fed through a quartz-nozzle, placed above the growth substrate. The influence of different growth-parameters was studied. Precursor flowrate, background-pressure, substrate material and nozzle-substrate distance were optimized for the experimental setup used. Local growth of polycrystalline graphene was achieved for small substrate-nozzle distance (2 mm) near atmospheric pressure (86.5 kPa) for low precursor flowrates (5 sccm). Local growth on both Cu and Cu0.88Ni0.12 is possible for these optimized parameters. Local graphene growth yield was found to be low. A possible explanation for the dependencies based on the fluid mechanics inside the furnace was found. An implementation of the local feeding setup was presented. Important parameters were optimized to allow local growth. Dependencies were studied to gain a better understanding of the local feeding growth mechanism.