Plasma CVD Engineering of Nitrogen-Vacancy Centers in (111) Single Crystal Diamond

Negatively charged nitrogen vacancy (NV-) centers will be high importance for a variety of quantum applications. Due to the long coherence time constant of NV- center even at room temperature, applications for quantum sensing, quantum information processing, and quantum register are very promising. Plasma-enhanced chemical vapor deposition (CVD) is one of the major approaches to introduce well-defined NV centers in diamond, as well as electron beam irradiation and ion implantation techniques. N-type Fermi control by phosphorus doping can offer charge-state stabilization of NV center, leading to longer coherent time at room temperature [1-3]. NV centers can be perfectly aligned along [111] axis by CVD growth on (111) surface [4,5]. Electrically excitation of NV defects and related readout with photo current, required to realize chip-scale magnetometers, have also been conducted by using diamond PIN junction diode structure [6-8]. All these achievements are based on our comprehensive progresses of CVD diamond growth, impurity doping, junction management, and device fabrication processes. Details will be discussed focusing on technical aspects peculiar to plasma CVD engineering of diamond NV centers.<br/>Acknowledgements: This work was partially supported by MEXT Q-LEAP (JPMXS0118067395), JST CREST (JPMJCR1773), MIC R&D (JPMI00316), and JST Moonshot R&D (JPMJMS2062).<br/>References: [1] H. Kato, et. al., Appl. Phys. Lett. 109, 142102 (2016). [2] Y. Doi, et. al., Phys. Rev. B 93, 081203(R) (2016). [3] E. D. Herbschleb, et. al., Nat. Commun. 10, 3766 (2019). [4] T. Fukui, et. al., Appl. Phys. Express 7, 055201 (2014). [5] T. Miyazaki, et. al., Appl. Phys. Lett. 105, 261601 (2014). [6] N. Mizuochi, et. al., Nat. Photonics 6, 299 (2012). [7] H. Kato, et. al., Appl. Phys. Lett. 102, 151101 (2013). [8] T. Murooka, et. al., Appl. Phys. Lett. 118, 253502 (2021).