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

摘要

Neutral impurity induced quantum well intermixing (QWI) is an attractive and promising postgrowth bandgap engineering process for the fabrication of photonic integrated circuits (PICs), as it introduces no additional electrical active dopants into the material system after intermixing. Here, we report the development of neutral impurity induced QWI processes in InGaAs-InGaAsP laser structure using low energy, i.e. 360keV, arsenic and phosphorous ion implantation. The samples were implanted at room temperature and 200 degrees C, with a dose range between 10$+12$/ and 10$+14$/ ions/cm$+2$/. The QWI stage was carried out by annealing the implanted samples at 650 degrees C for 120 s. Samples implanted at 200 degrees C give higher degree of QWI. Compared to P implanted samples, larger bandgap shift was observed form As implanted samples after annealing. A differential PL bandgap shift as large as 93 nm was observed from samples implanted with 10$+14$/ ions/cm$+2$/ of As. Bandgap tuned lasers fabricate from intermixed sample; the current threshold density of the intermixed lasers slowly increases with the amount of blueshift and is kept below 20 percent for the most blueshifted devices. The attractive device characteristics of the bandgap tuned lasers show that damage induced by the ion implantation can be almost fully tread after annealing. This implies that the material remains in good quality after QWI.