A competing bimodal lifetime distribution, incorporating the Joule heating effect, is adopted to describe the $p$ contact induced optical power failures occurring in GaAs nanoridge lasers monolithically integrated on 300 mm Si. Accelerated aging tests are performed at various temperatures and current densities to better understand the physics of the two dominant failure mechanisms - impurity diffusion and GaAs elemental interdiffusion. The activation energies and power law exponents for both mechanisms are determined by calibrating the junction temperatures using an experimentally validated electrothermal model. The former mechanism shows a weak current density dependence, suggesting a neutral diffusion source. In addition, the latter mechanism is linked to a recombination-enhanced process. Finally, lifetime projection is achieved by leveraging this model, enabling proposals of reliability-improved designs.

Reliability-improved GaAs nano-ridge lasers are fabricated on 300 mm silicon. A novel contact-FIN-based design, including an anisotropic InGaP passivation, ensures carrier injection while pulling down the optical modes. Single-facet power exceeding 10 mW is achieved at 25 °C.

The epitaxial growth of high-quality InGaAs/GaAs nano-ridges on silicon using aspect ratio trapping (ART) and nano-ridge engineering (NRE) has paved the way for the monolithic integration of laser sources on silicon. This breakthrough holds significant potential for integrated silicon photonics, enabling a wide range of applications and opening new research avenues. In this approach, the active material is grown not as a uniform layer but rather as parallel nano-ridge (NR) arrays. Leveraging this intrinsic feature of NRE, we propose a novel approach for realizing a surface-emitting laser and present the first experimental demonstration of this device. The device consists of an array of nano-ridges forming an in-plane cavity that can lase and couple light vertically. Based on an extensive design study, we demonstrate an optically pumped surface-emitting epitaxially grown nano-ridge laser (NRSEL) integrated on a 300 mm silicon wafer, which, to the best of our knowledge, is the first of its kind. We experimentally show lasing at the band edge of a photonic crystal by exploiting symmetry-protected bound states in the continuum (BICs). Additionally, we thoroughly characterize the far-field pattern. These findings lay the foundation for realizing high-density, integrated, and cost-effective electrically injected surface-emitting lasers on silicon.

Nano-ridge engineering (NRE) is a unique approach for the direct heteroepitaxial growth of III-V materials on 300 mm Si substrates. It builds upon selective area growth and aspect ratio trapping of misfit defects by depositing in high-aspect ratio trenches while innovating in its ability to increase the defect-free III-V volume via the growth out of the trenches, giving rise to large nano-ridges (NR). NRE was already successfully applied for the demonstration of electrically injected GaAs NR lasers fully processed in a CMOS prototyping line. The introduction of GaSb to the "NRE toolkit" would allow to further extend the emission wavelength. GaSb NRs where established in a previous study using either a thin GaAs or InAs seed layer on Si before switching to GaSb growth (Baryshnikova et al., 2020). Unfortunately, the choice of GaAs resulted in a low threading dislocation density (TDD) but high planar defect density (PDD) whereas the application of an InAs seed showed the opposite behaviour. Here, a GaSb seed was explored with the aim of lowering both defect types simultaneously. Studying different GaSb seed growth conditions, the same correlation between the presence of either a high PDD along with a low TDD or vice versa was observed. To improve upon both defect types at the same time, the application of an InGaSb seed (10-15% In) was investigated. The ternary seed allowed to enhance the nucleation of strain releasing misfit defects at the III-V/Si interface compared to the binary GaSb seed. This improvement reduces the risk of strain built-up during further GaSb growth, thereby avoiding new defect formation. Finally, the InGaSb seed enabled us to demonstrate GaSb NRs with record low TDD (similar to 1.105 cm-2) and PDD (similar to 0.1 mu m-1) in 400 nm high NRs.

We present the extraction of recombination coefficients for electrically injected monolithic nano-ridge laser diodes by first determining the effective carrier capture time from the small signal modulation response. The effect of the nano-ridge box size on the recombination coefficients is investigated.

The static and dynamic characteristics of electrically injected monolithic nano-ridge lasers emitting around the wavelength of 1030 nm are comprehensively investigated, providing critical insights into their performance and identifying pathways for future improvement. Key laser parameters such as the D-factor, the K-factor, the differential gain and the gain compression factor are extracted. Recombination coefficients and carrier escape times are determined by taking the effective carrier capture times derived from the small-signal modulation response. Additionally, the impact of the nano-ridge box size on the recombination coefficients is evaluated, highlighting the role of structural design in optimizing device performance and reliability.

A lifetime model is presented to study the diffusion-driven gradual degradation and the recombination-enhanced rapid failure in monolithic InGaAs/GaAs-on-Si nano-ridge lasers induced by high current density at p-contacts. Design guidelines are provided for improving reliability.

The integration of lasers on silicon photonics is often considered the "holy grail" of photonics, due to its potential to revolutionize various applications, including sensing, high-speed communication and computing. Silicon-based lasers can facilitate more capable and cost effective photonic integrated circuits (PICs). Aspect ratio trapping (ART) and nano-ridge engineering (NRE) enable the direct growth of high-quality, defect free, direct bandgap III-V semiconductors in the form of nano-ridges on the silicon substrate [1]. These techniques offer an attractive platform for silicon photonics, bringing us closer to realizing the full potential of this technology. Single nano-ridge optically pumped DFB lasers [2], PIN detectors, and more recently, electrically injected continuous-wave lasers have been showcased on this platform [3]. Here, we demonstrate a novel, optically pumped laser, leveraging the slow-light mode arising from the coupling of multiple InGaAs/GaAs nano-ridges in a one-dimensional photonic crystal configuration. This configuration serves to trap light in the form of a high Q-factor slow-light mode while simultaneously coupling it to vertical emission. We experimentally show low-threshold lasing (<= 10 kW/Cm<^>2) for a 20 times shorter cavity (similar to 15 mu m) than previously demonstrated DFB lasers. The laser operates in single mode with a high side-mode suppression ratio (SMSR) (>= 10 dB). Also, we studied the beam profile in depth, showing highly directional emission. We will present detailed simulation and experimental results.

This work investigates the reliability of a recent demonstration of the III-V laser fully fabricated in imec's 300 mm CMOS pilot line. A two-phase optical degradation is disclosed in such monolithic GaAs-on-Si nano-ridge quantum well lasers. Constant current aging tests reveal a gradual drift of the laser threshold current in phase I, which is attributed to the diffusion of impurities into quantum wells, resulting in a decrease of the non-radiative carrier lifetime. Subsequently, the high current density at metal/p-GaAs contacts induces an abrupt laser failure in phase II. Failure analysis on a device after 1000 h of electrical stress at room temperature reveals elemental interdiffusion in the GaAs nano-ridge under a p-contact plug, eventually punching through the quantum well, creating a leakage current path and inducing a diode breakdown. Detected failure modes are extrinsic and can be alleviated by dedicated contact and nano-ridge engineering (NRE). On the other hand, there is no evidence of recombination-enhanced dislocation reactions taking place close to the GaAs/Si interface, proving the successful confinement of misfit defects using high-aspect oxide trenches. The result sheds light on achieving reliable monolithic lasers for silicon photonics in high-bandwidth datacom applications.

Single-photon sources (SPSs) are essential for the development of practical quantum technologies, and their integration with silicon photonics is considered the preferred route for scalable implementations. To fully leverage the mature fabrication processes of CMOS foundries, we investigated the use of nano-ridge engineering (NRE) for the monolithic integration of InAs quantum dot (QD)-based SPSs on 300 mm Si wafers. These nano-ridges are made of high-crystal-quality GaAs selectively grown on a trench-patterned wafer, forming waveguides coplanar to the Si chip. The InAs QDs are embedded in these waveguides to form SPSs. In this work, a new device concept and integration approach is presented, showing that beta factors as high as 0.87 can be achieved owing to the high refractive index contrast between GaAs and SiO2. Then, a first proof of concept is demonstrated. Selective deposition of QDs on top of a diamond-shaped nano-ridge is used to center the dots within the final box-shaped nano-ridge, overgrown after the QD deposition, and to reduce the overall QD density per ridge. The grown QDs showed good spectral properties with line widths as low as 32.7 mu eV at 955 nm. The autocorrelation measurements from a selected QD underlines the single-photon nature of the grown structure, with a g 2(0) = 0.091 +/- 0.005 under nonresonant pulsed excitation. These findings establish a solid foundation for future advancements, including implementing a PIN junction to enhance indistinguishability and extending the emission wavelength to the telecommunication O-band via the growth on InGaAs nano-ridges.

We present a semi-analytical model that can accurately explain the working principle behind the recently reported electrically injected In0.2Ga0.8As/GaAs monolithic nano-ridge lasers and more importantly show how the model can be used to study the effect of device parameters on the spectral behavior, the slope efficiency and the threshold gain. We show that mode beating between the fundamental mode and a higher order mode is fundamental in the operation of these lasers. Analytical expressions for codirectional mode coupling are used in developing the round-trip laser model. Results from analytical expressions are verified by comparisons with simulations and the model is supported later by measurement results.

Monolithic integration of III-V compounds onto silicon (Si) substrates utilizing nano-ridge (NR) engineering holds great potential for developing optoelectronic devices that leverage the well-established CMOS process technology. To realize optimized processes that ensure high-quality growth of such novel three-dimensional structures, where feature sizes are in the nanometer range, reliable and rapid wafer-level monitoring is imperative. In this work, we develop an automated and scalable deep learning framework for intricate defect classification in NR structures using scanning electron microscopy images. The proposed method seeks to replace conventional, labor-intensive and error-prone manual defect inspection, significantly reducing turnaround time (TAT) and costs while improving classification accuracy. Furthermore, a graphical user interface (GUI) has been developed to enable efficient deployment in a 300 mm CMOS production environment.

Silicon photonics is a rapidly developing technology that promises to revolutionize the way we communicate, compute, and sense the world. However, the lack of highly scalable, native CMOS-integrated light sources is one of the main factors hampering its widespread adoption. Despite significant progress in hybrid and heterogeneous integration of III-V light sources on silicon, monolithic integration by direct epitaxial growth of III-V materials remains the pinnacle in realizing cost-effective on-chip light sources. Here, we report the first electrically driven GaAs-based multi-quantum-well laser diodes fully fabricated on 300 mm Si wafers in a CMOS pilot manufacturing line. GaAs nano-ridge waveguides with embedded p-i-n diodes, InGaAs quantum wells and InGaP passivation layers are grown with high quality at wafer scale, leveraging selective-area epitaxy with aspect-ratio trapping. After III-V facet patterning and standard CMOS contact metallization, room-temperature continuous-wave lasing is demonstrated at wavelengths around 1020 nm in more than three hundred devices across a wafer, with threshold currents as low as 5 mA, output powers beyond 1 mW, laser linewidths down to 46 MHz, and laser operation up to 55 {\deg}C. These results illustrate the potential of the III-V/Si nano-ridge engineering concept for the monolithic integration of laser diodes in a Si photonics platform, enabling future cost-sensitive high-volume applications in optical sensing, interconnects and beyond.

Amorphous-silicon-grating-on-top DFB-InGaAs/GaAs-laser directly grown on silicon substrate by nano-ridge engineering technique exhibits 2.5 kW/cm 2 lasing threshold, 10 times smaller than nano-ridge laser with etched grating, due to avoiding introducing carrier loss path at GaAs-air surface.

InAs quantum dots embedded in GaAs are a popular choice for the development of single photon sources. Nano-ridge engineering provides a route to monolithically integrate such sources on the silicon photonics platform.

We present a versatile III-V Heterojunction Bipolar Transistor (HBT) technology on 300 mm Si which can be adapted to RF applications ranging from microwave to mmWave bands. We demonstrate its potential by fabricating HBTs based on the InGaP/GaAsSb/InGaAs material system monolithically integrated on 300 mm Si substrate by varying the In and Sb content in the corresponding device layers while achieving a very low threading dislocation density (TDD) (<5x10(6) cm(-2)). An HBT device stack, grown lattice-matched to fully relaxed In0.3Ga0.7As nano-ridges on trench-patterned Si, shows >50x improvement in the collector current density as compared to our InGaP/GaAs HBTs without impacting the interface quality of underlying hetero-interfaces as indicated by the ideality factors of the base (similar to 1.8) and collector (similar to 1) currents, respectively. f(t) and f(max) of 36 GHz and 13.7 GHz, respectively, are reported for an emitter width of 5 mu m.

Compact on-chip sources with efficient emission in the O-band are a critical component for the silicon photonics platform to realize its full potential in telecom and datacom applications. III-V semiconductors are still the main candidates for realizing such sources but their significant lattice mismatch with silicon remains a fundamental challenge hampering monolithic integration. Hence, we need innovative methods to confine defects outside the active device region. Here, an ultra-compact 1.31 mu m-emission photonic crystal (PC) nano-ridge laser selectively area grown on a trench-patterned silicon substrate using aspect ratio trapping and nano-ridge engineering is demonstrated. Lasing at a remarkably low pumping threshold of 4.42 kW/cm(2) and with a cavity length as small as 50 mu m was realized with the PC nano-ridge device. The laser exhibits a lasing peak with side-mode suppression ratio of over 17 dB and a linewidth as narrow as 1.47 nm under 22.91 kW/cm(2) pulsed pumping. This PC nano-ridge laser opens a novel route to realize a compact light source for future high-density and massively scalable silicon photonic integrated circuits in the field of data communication.

We report on a comprehensive temperature dependent dark current study of high-quality InGaAs/GaAs multi quantum well waveguide photodetectors monolithically integrated on silicon. They are integrated through metalorganic vapor-phase selective-area epitaxial growth in a 300 mm CMOS pilot line. Defects resulting from the metamorphic growth of III-V devices on Si make these devices susceptible to different leakage mechanisms at higher operating temperatures. For the high-temperature operation of complex photonics-electronics integrations, understanding the leakage mechanisms of the devices has critical significance. This will help to optimize designs promptly and ensure the reliability and longevity of such devices under extreme operating conditions. The photodetector devices exhibit dark currents below 1 pA, at room temperature and -1 V bias voltage, limited by the noise floor of the measurement setup. To resolve the different leakage mechanisms contributing to the dark current, the devices were measured at elevated temperatures and the results were cross-validated with device simulations. The devices exhibited very low dark currents, with a median below 0.1 nA at 195 degrees C, suggesting very high-quality material growth. Through device models, leakage mechanisms related to Shockley-Read-Hall (SRH) recombination at bulk volume defects are found to be the main factor contributing to the dark current. The surface SRH recombination is found to be limited, yet affecting the forward bias dark current due to the shortening of the diffusion paths of the majority carriers. Also, the device model shows that the actual dark currents at room temperature can be as low as 0.01 pA, more than 1-order lower than the measured levels. This study emphasizes the high quality of the III-V nano-ridge waveguide devices grown on Si, which can potentially expand the capabilities of silicon photonics platforms further.

Abstract In this paper, the failure analysis of InGaAs/GaAs-on-Si nanoridge laser diodes using the electron beam based nano-probing technique is presented. These III-V laser devices are fabricated using the nano-ridge engineering approach where the misfit dislocations generated during the growth of InGaAs/GaAs layers on silicon substrate are confined away from the active region. It is observed that the applied electrical stress causes degradation of electrical properties of the laser devices. We demonstrate the application of the electron beam induced current (EBIC) technique for failure analysis of nano-ridge lasers. This high-resolution technique helps to visualize the local distribution of the electric field in a nano-ridge p-i-n diode. The EBIC signal from the reference (electrically unstressed) device and the electrically stressed device is compared and hence can be used to identify the defective region. Furthermore, in-situ electrical stress experiments are performed for systematic analysis of the impact of electrical stress on the EBIC results.