Effects of semiconductor processing chemicals on conductivity of graphene

Abstract

Graphene layers on SiO2/Si substrates were exposed to chemicals or gases commonly used in semiconductor fabrication processes, including solvents (isopropanol, acetone), acids, bases (ammonium hydroxide), UV ozone, H2O, and O-2 plasmas. The recovery of the initial graphene properties after these exposures was monitored by measuring both the layer resistance and Raman 2D peak position as a function of time in air or vacuum. Solvents and UV ozone were found to have the least affect, while oxygen plasma exposure caused an increase of resistance of more than 3 orders of magnitude. Recovery is accelerated under vacuum but changes can persist for more than 5 h. Careful design of fabrication schemes involving graphene is necessary to minimize these interactions with common processing chemicals. (C) 2012 American Vacuum Society. [http://dx.doi.org/10.1116/1.4732517]