Creation of colour centres in diamond by collimated ion-implantation through nano-channels in mica

The fabrication of scalable quantum devices in diamond relies on the ability to produce optical centres with a high spatial resolution. Ion implantation is the most powerful technique for placing impurity atoms in a diamond matrix. Even though shallow optical centres can be produced with a resolution below 20 nm, deep centres may be preferred for generally better overall properties. However, the focusing of ion beams in the MeV range can hardly be achieved below I rim. We present here a novel approach by implanting ions through a mask with high-aspect-ratio nano-channels and improve the collimation to below 50 nm. The mask contains parallel oriented channels of a few tens of nanometres in diameter. They are produced by exposing mica sheets to GeV heavy ion projectiles and subsequent track etching. We demonstrate the high-resolution creation of deep nitrogen-vacancy (NV) centres in diamond by implanting nitrogen ions through the nano-channels. Transmission rates and energy distribution of the nitrogen ions transmitted through the nano-channels were also analysed. (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim