Fabrication of strain-balanced Si0.73Ge0.27/Si-distributed Bragg reflectors on Si substrates for optical device applications

Si0.73Ge0.27/Si-distributed Bragg reflectors (DBRs) with high reflectivity were successfully fabricated by introducing the strain-balance method, which were designed to overcome the limitation of the number of pairs originating from the strain accumulation. X-ray diffraction spectra and Raman spectra of Si0.73Ge0.27/Si DBRs showed that Si0.73Ge0.27 and Si layers were under compressive and tensile strain on Si0.89Ge0.11 virtual substrates as designed. A record reflectivity of 83% was achieved at View the MathML source in the DBR with 28.5 pairs. The modulated luminescence was also observed from SiGe planar microcavity structures with strain-balanced SiGe/Si DBRs.