Optimized UV ozone cleaning of graphene layers on SiO2/Si substrates is shown to improve contact resistance of e-beam evaporated Ti/Au contacts by three orders of magnitude (3 × 10-6 Ω-cm 2) compared to untreated surfaces (4 × 10-3 Ω-cm2). Subsequent annealing at 300 °C lowers the minimum value achieved to 7 × 10-7 Ω-cm2. Ozone exposure beyond an optimum time (6 min in these experiments) led to a sharp increase in sheet resistance of the graphene, producing degraded contact resistance. The UV ozone treatment is a simple and effective method for producing high quality contacts to graphene.
|Journal||Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures|
|Publication status||Published - 2012 Nov 1|
ASJC Scopus subject areas
- Condensed Matter Physics
- Electrical and Electronic Engineering