Fabrication of graphene devices is often hindered by incompatibility between
the silicon technology and the methods of graphene growth. Exfoliation from
graphite yields excellent films but is good mainly for research. Graphene grown
on metal has a technological potential but requires mechanical transfer. Growth
by SiC decomposition requires a temperature budget exceeding the technological
limits. These issues could be circumvented by growing graphene directly on
insulator, implying Van der Waals growth. During growth, the insulator acts as
a support defining the growth plane. In the device, it insulates graphene from
the Si substrate. We demonstrate planar growth of graphene on mica surface.
This was achieved by molecular beam deposition above 600{\deg}C. High
resolution Raman scans illustrate the effect of growth parameters and substrate
topography on the film perfection. Ab initio calculations suggest a growth
model. Data analysis highlights the competition between nucleation at surface
steps and flat surface. As a proof of concept, we show the evidence of electric
field effect in a transistor with a directly grown channel.Comment: 13 pages, 6 figure
