Fabrication of Diamond Submicron Lenses and Cylinders by ICP Etching Technique with SiO₂ Balls Mask

Submicron lenses and cylinders exhibiting excellent properties in photodetector and quantum applications have been fabricated on a diamond surface by an inductively-coupled plasma (ICP) etching technique. During ICP etching, a layer containing 500 nm diameter balls of SiO₂ was employed as mask. By changing the mixing ratio of O₂, Ar and CF₄ during ICP etching, several submicron structures were fabricated, such as cylinders and lenses. The simulation results demonstrated that such submicron structures on a diamond's surface can greatly enhance the photon out-coupling efficiency of embedded nitrogen-vacancy center.