  By means of catalytic chemical vapor deposition (CCVD) in-situ grown
monolayer graphene field-effect transistors (MoLGFETs) and bilayer graphene
transistors (BiLGFETs) are realized directly on oxidized silicon substrate
without the need to transfer graphene layers. In-situ grown MoLGFETs exhibit
the expected Dirac point together with the typical low on/off-current ratios.
In contrast, BiLGFETs possess unipolar p-type device characteristics with an
extremely high on/off-current ratio up to 1E7. The complete fabrication process
is silicon CMOS compatible. This will allow a simple and low-cost integration
of graphene devices for nanoelectronic applications in a hybrid silicon CMOS
environment.
