Fabrication of GaAs laser diodes on Si using low-temperature bonding of MBE-grown GaAs wafers with Si wafers

Abstract

We present a study of the properties of III–V structures integrated on Si by low-temperature GaAs–Si wafer bonding, using an intermediate spin-on-glass layer. Transmission electron microscopy revealed the good quality of the bonding and the absence of micro-cracks or dislocations in the semiconductor material. Photoluminescence measurements on GaAs/AlGaAs multiple quantum well structures bonded on Si confirmed that the structural integrity of the quantum wells was preserved during the wafer bonding and thinning process. Photoreflectance measurements at temperatures in the range of 80–300 K showed that the bonded GaAs layers were practically stress free at room temperature, while a tensile stress appeared at lower temperature, due to the different thermal expansion coefficients of GaAs and Si. Laser devices with etched mirrors were fabricated on silicon and exhibited similar performances with reference devices fabricated on a GaAs substrate.