Free-Standing Mechanical and Photonic Nanostructures in Single-Crystal Diamond

Nano Letters (Impact Factor: 13.59). 11/2012; 12(12). DOI: 10.1021/nl302541e
Source: PubMed


A variety of nanoscale photonic, mechanical, electronic, and optoelectronic devices require scalable thin film fabrication. Typically, the device layer is defined by thin film deposition on a substrate of a different material, and optical or electrical isolation is provided by the material properties of the substrate or by removal of the substrate. For a number of materials this planar approach is not feasible, and new fabrication techniques are required to realize complex nanoscale devices. Here, we report a three-dimensional fabrication technique based on anisotropic plasma etching at an oblique angle to the sample surface. As a proof of concept, this angled-etching methodology is used to fabricate free-standing nanoscale components in bulk single-crystal diamond, including nanobeam mechanical resonators, optical waveguides, and photonic crystal and microdisk cavities. Potential applications of the fabricated prototypes range from classical and quantum photonic devices to nanomechanical-based sensors and actuators.

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Available from: Nathalie de Leon, Jan 21, 2014
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    • "Recent advances in annealing and surface passivation procedures [37] have significantly improved the ability to retain photostable NV centers generated by ion implantation even after fabrication of nanostructures around them [38]. Using these techniques in combination with our angled reactive ion etching (RIE) fabrication scheme [18] (details discussed in Appendix A), we were able to generate photostable NVs in diamond nano-cantilevers with a triangular cross section (Fig. 1 "
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    ABSTRACT: Nitrogen vacancy (NV) centers can couple to confined phonons in diamond mechanical resonators via the effect of lattice strain on their energy levels. Access to the strong spin-phonon coupling regime with this system requires resonators with nanoscale dimensions in order to overcome the weak strain response of the NV ground state spin sublevels. In this work, we study NVs in diamond cantilevers with lateral dimensions of a few hundred nm. Coupling of the NV ground state spin to the mechanical mode is detected in electron spin resonance (ESR), and its temporal dynamics are measured via spin echo. Our small mechanical mode volume leads to a 10-100X enhancement in spin-phonon coupling strength over previous NV-strain coupling demonstrations. This is an important step towards strong spin-phonon coupling, which can enable phonon-mediated quantum information processing and quantum metrology.
    Full-text · Article · Nov 2015
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    • "This etching technique can also be applied to etch other semiconductor materials and no additional mask is required to be deposited on the substrates . There are a few reports of using the Faraday cage to etch Si [18] [19], oblique incident angle etching of SiO 2 , Si 3 N 4 [20] and to etch diamond at certain angles [21]. Detailed modeling and functionality of Faraday cages in plasma etching can be found in [18–20,22–25]. "
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    ABSTRACT: Etching of diamond is one of the most important process steps to realize diamond based devices. Isotropic etching in diamond yielding a high etch rate is challenging owing to its material properties. In the current study, single-crystalline diamond is etched using a Faraday cage that acts as the mask to attain semi-isotropic etching. An oxygen/chlorine plasma discharge with a pressure of 10 mTorr is used. The etching process is optimized by varying the applied plasma power and the substrate bias and also by varying parameters such as the thickness of the mask, the mask-to-diamond surface distance, and the diameter of the holes in the mask. After optimization, the diamond substrates are etched to achieve semi-isotropic profile up to depths of 5 um with an etch rate of 80 nm/min and surface roughness close to that of the unetched surface.
    Full-text · Article · Aug 2015 · Diamond and Related Materials
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    ABSTRACT: We propose and analyze a novel mechanism for long-range spin-spin interactions in diamond nanostructures. The interactions between electronic spins, associated with nitrogen-vacancy centers in diamond, are mediated by their coupling via strain to the vibrational mode of a diamond mechanical nanoresonator. This coupling results in phonon-mediated effective spin-spin interactions that can be used to generate squeezed states of a spin ensemble. We show that spin dephasing and relaxation can be largely suppressed, allowing for substantial spin squeezing under realistic experimental conditions. Our approach has implications for spin-ensemble magnetometry, as well as phonon-mediated quantum information processing with spin qubits.
    Preview · Article · Jan 2013 · Physical Review Letters
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