Crystallographic Orientation Dependent Reactive Ion Etching in Single Crystal Diamond

Abstract

Sculpturing desired shapes in single crystal diamond is ever more crucial in the realization of complex devices for nanophotonics, quantum computing, and quantum optics. The crystallographic orientation dependent wet etch of single crystalline silicon in potassium hydroxide (KOH) allows a range of shapes to be formed and has significant impacts on microelectromechanical systems (MEMS), atomic force microscopy (AFM), and microfluidics. Here, a crystal direction dependent dry etching principle in an inductively coupled plasma reactive ion etcher is presented, which selectively reveals desired crystal planes in monocrystalline diamond by controlling the etching conditions. Using this principle, monolithic diamond nanopillars for magnetometry using nitrogen vacancy centers are fabricated. In these nanopillars, a half-tapering angle up to 21° is achieved, the highest angle reported in the literature, which leads to a high photon efficiency and high mechanical strength of the nanopillar. These results represent the first demonstration of a crystallographic orientation dependent reactive ion etching principle, which opens a new window for shaping specific nanostructures which is at the heart of nanotechnology. It is believed that this principle will prove to be valuable for the structuring and patterning of other single crystal materials as well.

Realizing Q> 300 000 in diamond microdisks for optomechanics via etch optimization

“…This process has seen adoption by researchers fabricating a variety of nanoscale structures from SCD [68][69][70] , and the properties of the quasi-isotropic etch and its interaction with the diamond crystal planes have been investigated in detail in Ref. 71 .…”

Recent Advances in Single Crystal Diamond Device Fabrication for Photonics, Sensing and Nanomechanics

“…Tailoring the scanning probe geometry can enhance photon collection, AFM capability and spatial resolution. Nanopillars with large taper angles obtained via plane dependent dry etching enhance photon collection due to the combined effect of optical wave guiding and adiabatic changes of the effective refractive index [ 52 ]. Figure 3 A,B show pillars with various taper angles.…”

Plasma treatments and photonic nanostructures for shallow nitrogen vacancy centers in diamond

“…It should be noted that the electrons might not fully transfer their thermal energy to the etching species but are still a clear indication of the plasma density [33]. In contrast in the case of a biased plasma, the energy of the etching species will be mainly governed by the DC bias [25]. We use the measured optical emission spectra of the plasmas to extract T el .…”