Monolithic integration of embedded III-V lasers on SOI

Abstract

Silicon photonic integration has gained great success in many application fields owing to the excellent optical device properties and complementary metal-oxide semiconductor (CMOS) compatibility. Realizing monolithic integration of III-V lasers and silicon photonic components on single silicon wafer is recognized as a long-standing obstacle for ultra-dense photonic integration, which can provide considerable economical, energy-efficient and foundry-scalable on-chip light sources, that has not been reported yet. Here, we demonstrate embedded InAs/GaAs quantum dot (QD) lasers directly grown on trenched silicon-on-insulator (SOI) substrate, enabling monolithic integration with butt-coupled silicon waveguides. By utilizing the patterned grating structures inside pre-defined SOI trenches and unique epitaxial method via hybrid molecular beam epitaxy (MBE), high-performance embedded InAs QD lasers with monolithically out-coupled silicon waveguide are achieved on such template. By resolving the epitaxy and fabrication challenges in such monolithic integrated architecture, embedded III-V lasers on SOI with continuous-wave lasing up to 85 °C are obtained. The maximum output power of 6.8 mW can be measured from the end tip of the butt-coupled silicon waveguides, with estimated coupling efficiency of approximately -6.7 dB. The results presented here provide a scalable and low-cost epitaxial method for the realization of on-chip light sources directly coupling to the silicon photonic components for future high-density photonic integration.

Design Rules for Addressing Material Asymmetry Induced by Templated Epitaxy for Integrated Heteroepitaxial On‐Chip Light Sources

“…Both passive and active waveguide coupling have been demonstrated in such a configuration. [ 14,15 ] The first electrically pumped QD lasers deposited in narrow pockets by MBE have also been demonstrated on 300 mm Si photonic wafers with comparable reliability to those grown on planar Si substrates at a similar defect density. [ 16 ]…”

Monolithic Quantum Dot Discrete Mode Laser on SOI

“…To smoothen the surface of GaAs/SOI substrates, the AlGaAs/GaAs superlattice structures were grown over the top of DLF layers. The growth details and material characterizations of the GaAs/SOI template can be found in our previous work. − …”

“…The (111)-faceted Si sawtooth template was then in situ transferred into the III–V chamber for the following III–V buffer layer growth. Here, the standard two-step growth process was used for the heteroepitaxial growth of GaAs layers. − To reduce the threading dislocation density, the InGa­(Al)­As/GaAs quantum well layers were grown as dislocation filters (DLFs). To smoothen the surface of GaAs/SOI substrates, the AlGaAs/GaAs superlattice structures were grown over the top of DLF layers.…”

“…GHz at an injection current of 170 mA. By implementing trenched selective area growth, 26 this monolithic DM laser on SOI can potentially provide a high-yield and low-cost path to fabricate silicon photonic compatible single-mode lasers while also offering an alternative approach for future on-chip integration.…”

Lateral Tunnel Epitaxy of GaAs in Lithographically Defined Cavities on 220 nm Silicon-on-Insulator

“…8,9 Efficient coupling from the epitaxial lasers to Si waveguides remains a critical challenge to date. 10,11 Recent development in lateral epitaxy, a growth technique also demonstrated in Si tunnel epitaxy, 12 has shown the potential of growing "buffer-less" dislocation-free III−V materials on SOI substrates. 13−18 It brings the III−V optical active region in close proximity to Si which has enabled highperformance waveguide coupled photodetectors.…”