Photonic integration of InGaAs-InGaAsP laser using low-energy-implantation-induced quantum well intermixing

Abstract

ABSTRACT Neutral impurity induced quantum well intermixing (QWI) is an attractive and promising postgrowth bandgap engineeringprocess for the fabrication of photonic integrated circuits (PICs), as it introduces no additional electrical active dopants intothe material system after intermixing. Here, we report the development of neutral impurity induced QWI processes inInGaAs-InGaAsP laser structure using low energy, i.e. 36OkeV, arsenic and phosphorous ion implantation. The samples wereimplanted at room temperature and 200 °C, with a dose range between 1012 and 1014 ions/cm2. The QWI stage was carried outby annealing the implanted samples at 650 °C for 120 s. Samples implanted at 200 °C give higher degree ofQWI. Comparedto P implanted samples, larger bandgap shift was observed from As implanted samples after annealing. A differential PLbandgap shift as large as 93 nm (60 meV) was observed from samples implanted with iO' ions/cm2 of As. Bandgap tunedlasers fabricated from intermixed samples; the current threshold density of the intermixed lasers slowly increases with theamount of blueshift and is kept below 20% for the most blueshifted devices. The attractive device characteristics of thebandgap tuned lasers show that damage induced by the ion implantation can be almost fully treated after annealing. Thisimplies that the material remains in good quality after QWI.Keywords: Low energy ion implantation, quantum well Intermixing, InGaAs-InGaAsP, quantum well laser.