Development of SiC/MgO Distributed Bragg Reflector using RF Magnetron Sputtering Technique

A Bragg mirror structure is an essential part for vertical cavity surface emission laser (VCSEL) applications. High optical reflectance at required stopband width is one of major concern by means of application requirements. For this purpose, Bragg mirrors consisting of SiC/MgO multilayers have been developed using an RF magnetron sputtering technique at room temperature. These structures have been characterized using various measurement techniques like ellipsometry, reflectance spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) technique. From these measurements, it was confirmed that mirror materials were deposited on the substrates. For application requirement, the DBR mirror structure fabricated using only a seven period SiC/MgO multilayered structure produced the expected stop-band at 850 nm wavelength with high reflectivity of 95%.