New Electrochemical Based Polishing Methods for Processing Diamond Surfaces

Diamond is a material that has many extreme properties which has enabled technology and performance advances in many fields, including increased laser and microwave power densities in industrial cutting / fusion, quantum information processing and communication, magnetic and electric field sensing, radiation-hard particle detectors and electrochemical sensing and waste water clean-up. Key to optimizing performance in many of these applications is preparation of a defect /damage free surface and near surface region. This is incredibly challenging as diamond is unlike materials such as silicon or metals, where procedures are known for preparing high quality surfaces. The most common method for reducing surface roughness in diamond is to mechanically polish. However, this in itself is well-known for introducing polishing lines and sub-surface damage. The overall aim of this project is to develop new chemical and electrochemical based methods of removing material from the diamond surface to significantly reduce surface roughness, remove polishing lines and minimize surface defects and sub- surface defect formation, while maintain high
levels of flatness and smoothness. The material will be tested in different electrochemical and optical applications.

The project will involve but is not limited to:

- Investigate electrochemical methods of producing diamond etchant species capable of removing diamond in a controlled and defect free manner, initially working with boron doped material
- Development of a combined UV-electrochemical system for work with undoped diamond, where the UV acts to significantly increase the charge carrier concentration in diamond
- Proving the technology works with >100's microns thick as well as < 50 micrometre thick diamond
- Exploration of combined electro(chemical)-mechanical polishing methods
- Training in electrochemical and surface science characterisation techniques
- Investigation of prepared surfaces in different applications, comparison against state-of -the-art mechanically polished and plasma etched surfaces