Monolithically Integrated Electrically Pumped Continuous-Wave III-V Quantum Dot Light Sources on Silicon

Abstract

In this paper, we report monolithically integrated III-V quantum dot (QD) light-emitting sources on silicon substrates for silicon photonics. We describe the first practical InAs/GaAs QD lasers monolithically grown on an offcut silicon (001) substrate due to the realization of high quality III-V epilayers on silicon with low defect density, indicating that the large material dissimilarity between III-Vs and silicon is no longer a fundamental barrier limiting monolithic growth of III-V lasers on Si substrates. Although the use of offcut silicon substrates overcomes the antiphase boundary (APB) problem, it has the disadvantage of not being readily compatible with standard microelectronics fabrication, where wafers with on-axis silicon (001) substrates are used. We therefore report, to the best of our knowledge, the first electrically pumped continuous-wave (c.w.) InAs/GaAs QD lasers fabricated on on-axis GaAs/Si (001) substrates without any intermediate buffer layers. Based on the achievements described above, we move on to report the first study of post-fabrication and prototyping of various Si-based light emitting sources by utilizing the focused ion beam (FIB) technique, with the intention of expediting the progress toward large-scale and low-cost photonic integrated circuits monolithically integrated on a silicon platform. We compare two Si-based QD lasers with as-cleaved and FIB-made facets, and prove that FIB is a powerful tool to fabricate integrated Manuscript lasers on silicon substrates. Using angled facet structures, which effectively reduce facet reflectivity, we demonstrate Si-based InAs/GaAs QD superluminescent light emitting diodes (SLDs) operating under c.w. conditions at room temperature for the first time. The work described represents significant advances towards the realization of a comprehensive silicon photonics technology.Index Terms-Molecular beam epitaxy, quantum dots, semiconductor lasers, silicon photonics, focused ion beam. College London, where he is currently a Professor of semiconductor photonics. His research interests include the nanometer-scale engineering of low-dimensional semiconductor structures (such as quantum dots, quantum wires, and quantum wells) by using molecular beam epitaxy and the development of novel optoelectronic devices including lasers, detectors, and modulators by developing novel device process techniques. He has co-authored more than 300 papers in the area of semiconductor materials and devices.

Parametric study of high-performance 155 μm InAs quantum dot microdisk lasers on Si

“…1(a). The III-V on silicon structures employed here eliminate the utilization of either patterned Si substrates that require nanopattern lithography and etching processes [13], or specialized offcut Si wafers not commonly used in CMOS fabs and cost-intensive [14]. Our developed InP-on-Si (IoS) template technology can ease the transfer of incumbent InP-based optoelectronic devices and PIC technologies onto the advanced Si manufacturing platform [15][16][17][18], contributing to future dense optoelectronic integration and high speed data communications.…”

The effect of post-growth rapid thermal annealing on InAs/InGaAs dot-in-a-well structure monolithically grown on Si

“…The growth details of the InAs/InGaAs dot-in-well (DWELL) structure monolithically grown on Si substrates have been shown by Wang et al 21,22 The schematic sample structure and crosssection bright field scanning transmission electron microscopy (BF-STEM) image of the as-grown sample are shown in Figs. 1(a) and 1(b), respectively.…”

O-band InAs Quantum Dot Light Sources Monolithically Grown on Si

“…Lasing characteristics for silicon-based lasers with FIB-created facets and as-cleaved facets were compared, and the initial results reveal that there was no obvious deterioration between these two facet realization approaches. Various Si-based light emitting sources, such as lasers, superluminescent diodes (SLDs) [11] and LEDs, were then realized by effectively reduced facet reflectivity using focused Ga+ ion beam milling of the front facet of the edge emitting Si-based InAs/GaAs QD laser [12].…”