Owing to its high electrical conductivity, low density,
and flexibility, graphene has great potential for use as a building
block in a wide range of applications from nanoelectronics to biosensing
and high-frequency devices. For many device applications, it is required
to deposit dielectric materials on graphene at high temperatures and
in ambient oxygen. This has been proven to be highly challenging because
these conditions cause significant degradation in graphene. In this
work, we investigate the degradation of graphene at elevated temperatures
in an oxygen atmosphere and possible protection mechanisms to enable
the growth of oxide thin films on graphene at higher temperatures.
We show that coating graphene with self-assembled monolayers of hexamethyldisilazane
(HMDS) prior to a high-temperature deposition can significantly reduce
the damage induced. Furthermore, a graphene sample treated with HMDS
displayed a weaker doping effect due to weak interaction with oxygen
species than bare graphene, and a much slower rate of electrical resistance
degradation was exhibited during annealing. Thus, it is a promising
approach that could enable the deposition of metal oxide materials
on graphene at high temperatures without significant degradation in
graphene quality, which is critical for a wide range of applications.