Focused ion beam (FIB) microscopes are versatile nanofabrication tools that allow the arbitrary 3D patterning of shallow surfaces with nanometre precision. However this capability comes with two significant limitations: firstly that implantation of ions generates near surface damage which can be detrimental to the operation of electronic and optical devices, and secondly that the technique is relatively slow and costly, not well suited for large-scale fabrication.
This project seeks to address both of these limitations by exploring ways to transfer precision FIB-milled surfaces into secondary materials, thereby to fabricate novel microphotonic devices at scale. Two approaches will be tried: lithography using chemical etching and nanoimprint lithography. In each case FIB will be used to produce the primary surface (the etch mask or nanoimprint stamp), followed by the transfer process. The goal of the project will be to fabricate precision microcavity arrays containing fluorescent material, (eg organics dyes, colour centres, quantum wells) such that the fluorescent properties are maintained.
The project will be carried out in communication with Oxford HighQ Ltd, a spin-out company originating from the group and utilising FIB milling in photonic device fabrication.