Deep-UV hexagonal boron nitride (hBN)/BAlN distributed Bragg reflectors fabricated by RF-sputtering

Abstract

The hexagonal boron nitride (hBN) and BAlN films were prepared by RF-sputtering, which were used as the low and high refractive index layers. A series of hBN/BAlN distributed Bragg reflectors (DBRs) were prepared on sapphire substrate. The reflectivity of 9-pair hBN/BAlN (39 nm/33 nm) DBR reached 90% at 300 nm with a bandwidth of 45 nm, and which of 6-pair hBN/BAlN (35 nm/29 nm) reached 52% at 280 nm. The hBN/BAlN DBRs can be used to achieve higher reflectivity in shorter UV bands with the improvement of BAlN material quality through the growth condition optimization.