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

Hong-Xing Wang,Wei Wang,Tian-Fei Zhu,Shuwei Fan,Zongchen Liu,Xiaofan Zhang,Irfan Ahmed,Feng Wen,Yan-Feng Wang,Zhangcheng Liu,Kaiyue Wang

doi:10.3390/ma12101622

Abstract

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.

Highlights

The negatively charged nitrogen-vacancy (NV− ) center in diamond emitting single photon with 637 nm wavelength has appeared as a promising quantum light source [1]
By controlling inductively-coupled plasma (ICP) reactive gas component and etching time, several submicron structures were obtained on the diamond surface
By using Lumerical finite-difference time-domain (FDTD) Solutions, simulations were performed to obtain and optimize photon collection efficiency of NV− centers embedded in bulk diamond, submicron lenses and submicron cylinders

Summary

Introduction

The negatively charged nitrogen-vacancy (NV− ) center in diamond emitting single photon with 637 nm wavelength has appeared as a promising quantum light source [1]. Center in applications and diamond photonic devices are limited by low photon in- and out-coupling efficiency [13,14,15]. Some experiment schemes were performed to fabricate micro lenses on a diamond surface to improve photo response of photodetectors and the efficiency of embedded NV− center [16,17,20]. These works have greatly improved the developments of diamond photodetectors and applications of NV− center. Photolithography and ICP etching techniques had been used to fabricate micro lenses whose sizes were limited by resolution of photolithography [16,20,23]. Electron beam lithography or dual mask technique and ICP etching techniques were used to fabricate micro cylinders [19,24,25]

Methods

Results

Conclusion