Shadow walls for use in fabricating devices

A method of fabricating a device, which method includes:

• fabricating a shadow wall on a substrate, the shadow wall including a base portion and a bridge portion by:
• forming a first resist on the substrate, the substrate including a wafer and a dielectric mask for controlling selective area growth arranged on the wafer, the dielectric mask including an opening;
• selectively exposing a portion of the first resist and developing the first resist to form a mask defining a channel;
• forming a second resist in the channel and over the mask, wherein the first resist and the second resist include different materials;
• and
• selectively exposing a portion of the second resist, developing the second resist, and removing the mask defining the channel to form the shadow wall;
• and
• directionally depositing a material from a direction selected such that the directionally deposited material is not deposited in a region defined by a shadow cast on the substrate by the shadow wall, wherein
• the base portion is formed in the channel;
• the base portion supports the bridge portion;
• the base portion is spaced from the opening by a distance of less than or equal to 1.5 μm;
• the bridge portion overhangs the substrate;
• the material is deposited via a directed beam of material;
• and
• the directed beam has a constant azimuth relative to a surface of the substrate during deposition.