Selective quantum dot intermixing for photonic devices

Dielectric-cap-based techniques, originally developed for quantum well intermixing, have been applied to the intermixing of InGaAs/GaAs/AlGaAs QD material with an emission wavelength of 1280 nm. Intermixing was achieved by sputtering a QDI-enhancing cap in some areas, and plasma deposition of silica QDI-suppressing cap in other areas, followed by a high-temperature anneal cycle. Extremely large bandgap blue-shifts of up to 280 nm have been obtained with an anneal temperature of 800 C. Selected intermixing was obtained by varying the coverage density of QDI-enhancing features over that of QDI-suppressing ones.