Atomic layer etching of diamond using argon and oxygen

Kurzfassung

The ability to remove surface defects of diamond by dry etching methods is of high importance for applications that make use of shallow color centers in diamond. Here, we present an atomic layer etching process, making use of oxygen as dosing gas and argon as etching gas, in order to achieve controlled etching of the surface without creating additional defects by sputtering. We demonstrate a process window, where quasi-self-limiting atomic layer etching takes place with an etch per cycle of (1.909 ± 0.004) Å/cycle, corresponding to about 2 atomic layers of the {100} oriented diamond sample. The process is able to reduce the rms surface roughness down to (0.15 ± 0.01) nm. Furthermore, X-ray photoelectron spectroscopy indicates only a small amount of sp2 bonded carbon on the diamond surface after the atomic layer etching process.