Abstract: A method of fabricating a hollow wall for controlling directional deposition of material comprises: forming a layer of resist on a substrate; removing a portion of the resist selectively to form a channel in the resist; forming a layer of an amorphous dielectric material in the channel; and removing the resist to form the hollow wall. The channel has a front surface configured to prevent bending of a corresponding front face of the hollow wall. The hollow wall is useful for controlling deposition of material when fabricating semiconductor-superconductor hybrid devices, for example. By configuring the channel appropriately, bending of the hollow wall can be prevented, allowing for more precise deposition of material. Also provided is a further method of fabricating a hollow wall; and a method of fabricating a device using the hollow walls.