Regaining a spatial dimension: mechanically-transferrable 2D InAs nanofins grown by selective area epitaxy

We report a method for growing rectangular InAs nanofins with deterministic length, width and height by dielectric-templated selective-area epitaxy. These freestanding nanofins can be transferred to lay flat on a separate substrate for device fabrication. A key goal was to regain a spatial dimension for device design compared to nanowires, whilst retaining the benefits of bottom-up epitaxial growth. The transferred nanofins were made into devices featuring multiple contacts for Hall effect and four-terminal resistance studies, as well as a global back-gate and nanoscale local top-gates for density control. Hall studies give a 3D electron density 2.5 - 5 × 1017 cm-3, corresponding to an approximate surface accumulation layer density 3 - 6 × 1012 cm-2 that agrees well with previous studies of InAs nanowires. We obtain Hall mobilities as high as 1200 cm2/Vs, field-effect mobilities as high as 4400 cm2/Vs and clear quantum interference structure at temperatures as high as 20 K. Our devices show excellent pros...