  Metal-assisted chemical etching of silicon is a promising method for
fabricating nanostructures with a high aspect ratio. To define a pattern for
the catalyst, lift-off processes are commonly used. The lift-off step however
is often a process bottle neck due to low yield, especially for smaller
structures. To bypass the lift-off process, other methods such as
electroplating can be utilized. In this paper, we suggest an electroplated
bi-layer catalyst for vapour phase metal-assisted chemical etching as an
alternative to the commonly utilised lift-off process. Samples were
successfully etched in vapour, and resulting structures had feature sizes down
to 10 nm.
