Chemical etching of silicon assisted by a number of catalysts
is
attracting increasing attention in the fabrication of silicon micro–nanostructures.
In practical applications, metal-free catalysts, including carbon
materials, have been focused on as alternative materials for the assisted
etching of silicon. Although this anisotropic etching process is suitable
for the fabrication of silicon micro–nanostructures due to
its simplicity and cost effectiveness, a number of challenges remain,
such as the formation of a
porous layer and peeling of the catalyst by the gases produced during
the etching process. We herein report vapor-phase etching assisted
by graphene oxide and its mechanism in terms of reaction kinetics.
By optimizing etching conditions, graphene oxide enhances the etching
reaction in the vapor phase without the formation of a porous layer.
We also demonstrated the formation of micrometer-sized pores in the
desired areas by combining the microcontact printing of graphene oxide
with silicon etching in the vapor phase.