Fabrication of multi-wavelength In0.2Ga0.8As/GaAs multiple quantum well laser diodes by area-selective impurity-free vacancy disordering using SiOx capping layers with different stoichiometries

Abstract

This work studied the implementation of multiwavelength laser diodes on a single substrate through the position-dependent bandgap modification of the In0.2Ga0.8As/ GaAs multiple quantum wells (MQWs) by impurity-free vacancy disordering (IFVD). The position-dependent bandgap modification is achieved by performing the IFVD with SiOx capping layers with different stoichiometries. The lasing wavelength difference of about 31 nm was obtained between the ridge-waveguide laser diodes fabricated with the MQWs that had undergone the same thermal treatments using the SiOx film provided with SiH4 flow rates of 20 and 300 sccm. The device performance was not appreciably degraded in the laser diodes fabricated with the MQWs that had undergone the IFVD process.