Aurion's heterogeneous integration platform combines best-in-class passive and active devices in a cost-effective manufacturing process for both military and commercial systems. The resulting silicon photonics chips can be intimately integrated with advanced electronics to enable new system-in-package capability.
Aurrion’s heterogeneous integration process enables high performance active components such as lasers, modulators, and photodetectors to be elegantly integrated on a silicon photonics platform with high performance passive components. This platform also offers the unique capability to combine different types of active devices with separately optimized materials on the same wafer, die, and photonic integrated circuit. Similarly, devices and photonic integrated circuits operating in different wavelength bands can be formed within the same wafer and die. Experimental demonstrations show that these active components can achieve performance on par with commercially available discrete III-V components. In this paper we will discuss the advantages of Aurrion’s heterogeneous integration platform and discuss prototype demonstrations.
Photonic Integrated Circuits (PICs) have been dichotomized into circuits with high passive content (silica
and silicon PLCs) and high active content (InP tunable lasers and transceivers) due to the trade-off in material
characteristics used within these two classes. This has led to restrictions in the adoption of PICs to systems in which
only one of the two classes of circuits are required to be made on a singular chip. Much work has been done to
create convergence in these two classes by either engineering the materials to achieve the functionality of both
device types on a single platform, or in epitaxial growth techniques to transfer one material to the next, but have yet
to demonstrate performance equal to that of components fabricated in their native substrates. Advances in waferbonding
techniques have led to a new class of heterogeneously integrated photonic circuits that allow for the
concurrent use of active and passive materials within a photonic circuit, realizing components on a transferred
substrate that have equivalent performance as their native substrate. In this talk, we review and compare advances
made in heterogeneous integration along with demonstrations of components and circuits enabled by this technology.
A compact electrically-pumped hybrid silicon microring laser is realized on a hybrid silicon platform. A simplified, selfaligned,
deep-etch process is developed to result in low-loss resonator with a high quality factor Q>15,000. Small
footprint (resonator diameter=50 μm), electrical and optical losses all contribute to lasing threshold as low as 5.4 mA and
up to 65 °C operation temperature in continuous-wave (cw) mode. Outcoupling- and bus waveguide width-dependent
studies are conducted for optimizing device structure. A simple qualitative study in current-voltage (IV) characteristic
shows that dry etching through active region leads to <3× more leakage current at the same reverse bias than wet etch
counterpart. It indicates a relatively good interface with tolerable surface recombination from deep dry etch. The
spectrum is single mode with large extinction ratio (>40 dB) and small linewidth (<0.04 nm) observed. The unique
bistability operation in ring resonator structure is also demonstrated.
Single wavelength hybrid silicon evanescent lasers are described based on wafer bonding III-V multiple quantum wells
to gratings patterned on a silicon waveguide. Distributed Bragg feedback and distributed Bragg reflector lasers are
demonstrated integrated with passive silicon waveguides showing thresholds as low as 25mA and output powers as high
as 11mW around 1600nm wavelength.
Abstract 100 mm wafer bonding of InP-based structure and silicon-on-insulator wafers is presented with the use of a lowtemperature
(300 °C) O2 plasma-assisted wafer bonding process. An efficient vertical outgassing channels (VOCs) design
is developed to eliminate the fundamental obstacle of interfacial voids in bonding due to intrinsic chemical reactions.
Generated gas species of H<sub>2</sub>O and H<sub>2</sub> can quickly diffuse to VOCs, etched through-holes to buried oxide layer (BOX), and
absorbed by the BOX layer owing to the open network structure and large gas permeability. The interfacial void density is
reduced from 55,093 cm<sup>-2</sup> down to 3 cm<sup>-2</sup>, more than five orders of magnitude reduction for appropriate design of VOCs.
Uniform patterning of VOCs leads to no outgassing "dead zone" across the entire bonding area, and decrease of the
thermal mismatch-induced interfacial strain potentially as well, which both result in the wafer scale-independent bonding.
In addition, we present distributed feedback silicon lasers realized on the hybrid silicon evanescent platform. The laser
operates continuous wave with a single mode output at 1600 nm. A continuous wave (CW) low threshold of 25 mA with a
maximum output power of 5.4 mW is demonstrated at 10 °C. The obtained side mode suppression ratio of 50 dB, 3.6
MHz linewidth, and over 100 nm single mode operation band are comparable to those of commercial III-V DFB devices.
These highly single mode lasers may find applications in computer interconnect.
Recently, AlGaInAs-silicon evanescent lasers have been demonstrated as a method of integrating active photonic devices on a silicon based platform. This hybrid waveguide architecture consists of III-V quantum wells bonded to silicon waveguides. The self aligned optical mode leads to a bonding process that is manufacturable in high volumes. Here give an overview of a racetrack resonator laser integrated with two photo-detectors on the hybrid AlGaInAs-silicon evanescent device platform. Unlike previous demonstrations of hybrid AlGaInAs-silicon evanescent lasers, we demonstrate an on-chip racetrack resonator laser that does not rely on facet polishing and dicing in order to define the laser cavity. The laser runs continuous-wave (c.w.) at 1590 nm with a threshold of 175 mA, has a maximum total output power of 29 mW and a maximum operating temperature of 60 C. The output of this laser light is directly coupled into a pair of on chip hybrid AlGaInAs-silicon evanescent photodetectors used to measure the laser output.
Recently, AlGaInAs-silicon evanescent lasers have been demonstrated as a method of integrating active
photonic devices on a silicon based platform. This hybrid waveguide architecture consists of III-V quantum wells
bonded to silicon waveguides. The self aligned optical mode leads to a bonding process that is manufacturable in high
volumes. Here give an overview of a racetrack resonator laser integrated with two photo-detectors on the hybrid
AlGaInAs-silicon evanescent device platform. Unlike previous demonstrations of hybrid AlGaInAs-silicon evanescent
lasers, we demonstrate an on-chip racetrack resonator laser that does not rely on facet polishing and dicing in order to
define the laser cavity. The laser runs continuous-wave (c.w.) at 1590 nm with a threshold of 175 mA, has a maximum
total output power of 29 mW and a maximum operating temperature of 60 C. The output of this laser light is directly
coupled into a pair of on chip hybrid AlGaInAs-silicon evanescent photodetectors used to measure the laser output.
We present an electrically pumped silicon evanescent laser that utilizes a silicon waveguide and offset AlGaInAs
quantum wells. The silicon waveguide is fabricated on a Silicon-On-Insulator (SOI) wafer and is bonded with the
AlGaInAs quantum well structure using low temperature O<sub>2</sub> plasma-assisted wafer bonding. The optical mode in the
hybrid waveguide is predominantly confined in the passive silicon waveguide and evanescently couples into the III-V
active region providing optical gain via electrical current injection. The device lases continuous wave at 1577 nm with a
threshold of 65 mA at 15 °C. The maximum single-sided fiber-coupled cw output power is 1.8 mW. The maximum operating temperature is 40 °C mainly limited by a high series resistance of the device. Operation up to 60 °C should be achievable by lowering the series resistance and thermal impedance.
In recent years there has been a growing interest in using Silicon on Insulator (SOI) as a platform for integrated planar optical circuits, this is mainly due to the high quality yield volume processes demonstrated by the CMOS manufacturing industry and recent MEMS technology progress. In this work we present monolithic integration of Silicon and SiON planar lightwave circuits on a single SOI chip processed in a CMOS fabrication environment. The demonstration of a processing scheme that yields low loss waveguides for both silicon and SiON as well as efficient transition of light between the two materials is the goal of this present work. The patterning of waveguides in both silicon and SiON regions is done in a self aligned process using one lithography mask and two separate dry etch steps each highly selective to one of the two materials. The effect of a high temperature anneal on the IR absorption of SiON related N-H bond was measured using FTIR and waveguide optical loss. Up to 98% reduction in absorption is demonstrated which allows acceptable loss across the C-band. We have achieved low propagation loss, single mode, and rib waveguides for both Silicon and SiON core regions as well as low loss silicon-SiON waveguides junction. The silicon-SiON junction loss has been measured to be 0.9+/-0.1dB, only 0.3dB greater than the theoretical value determined by Fresnel's facet reflection.
We report a novel laser architecture, the silicon evanescent laser (SEL), that utilizes a silicon waveguide and offset AlGaInAs quantum wells. The silicon waveguide is fabricated on a Silicon-On-Insulator (SOI) wafer using a CMOS-compatible process, and is bonded with the AlGaInAs quantum well structure using low temperature O2 plasma-assisted wafer bonding. The optical mode in the SEL is predominantly confined in the passive silicon waveguide and evanescently couples into the III-V active region providing optical gain. This approach combines the advantages of high gain III-V materials and the integration capability of silicon technology. Moreover, the difficulty of coupling an external laser source is overcome as the hybrid waveguide can be self-aligned to silicon-based passive optical devices. The SEL lases continuous wave (CW) at 1568 nm with a threshold of 23 mW. The maximum single-sided fiber-coupled CW output power is 4.5 mW. The SEL characteristics are dependent on the silicon waveguide dimensions resulting in different confinement factors in the III-V gain region.