Hybrid Integration Research Articles

Execution of an applicable hybrid integration procedure for mineral prospectivity mapping

Execution of an applicable hybrid integration procedure for mineral prospectivity mapping

A Detailed Analysis of Wafer Scale Integration and Multichip Modules

Hybrid integration of functional multichip layers and electronic devices has received a significant research interest from both industry and academia. While moving towards the end of Moore's law, the power consumption and device scaling remain as significant challenges, necessitating the development of beyond-multichip technologies to achieve high performance computing. While conventional techniques like wafer based bonding and pick-and-place can only partially address the aforementioned challenges, a variety of new multi-chip transfer and wafer scale circuit integration approaches have been developed. This review summarizes such wafer scale integration and neural networks based on multichip modules for many applications, such as flexible electronics, smart displays, and gaming. The proposed study has showcased a wide range of multi-chip modules, and the need for wafer scale integration with expanded functionalities. Finally, a detailed analysis on the advantages of the state-of-the-art techniques has been provided and the future research directions are discussed.

A Detailed Analysis of Wafer Scale Integration and Multichip Modules

Hybrid integration of functional multichip layers and electronic devices has received a significant research interest from both industry and academia. While moving towards the end of Moore's law, the power consumption and device scaling remain as significant challenges, necessitating the development of beyond-multichip technologies to achieve high performance computing. While conventional techniques like wafer based bonding and pick-and-place can only partially address the aforementioned challenges, a variety of new multi-chip transfer and wafer scale circuit integration approaches have been developed. This review summarizes such wafer scale integration and neural networks based on multichip modules for many applications, such as flexible electronics, smart displays, and gaming. The proposed study has showcased a wide range of multi-chip modules, and the need for wafer scale integration with expanded functionalities. Finally, a detailed analysis on the advantages of the state-of-the-art techniques has been provided and the future research directions are discussed.

Multi-Static Multi-Band Synthetic Aperture Radar (SAR) Constellation Based on Integrated Photonic Circuits

Multi-static SARs from LEO orbits allow the single-pass high-resolution imaging and detection of moving targets. A coherent MIMO approach requires the generation of multi-band, thus orthogonal, signals, the fusion of which increases the system resolution. Up to now the synchronization capability of SAR signals of different satellites is critical. Here, we propose the use of photonics to generate, receive and distribute the radar signals in a coherent multi-static SAR constellation. Photonics overcomes issues in the implementation of MIMO SAR, allowing for the flexible generation of multi-band signals and centralized generation in a primary satellite with coherent distribution to all the secondary satellites of the SAR signals over FSO links. The numerical analysis shows the proposed system has a NESZ < −29.6 dB, satisfying the SAR system requirements. An experimental proof of concept based on COTS, for both signal up- and down-conversion, is implemented to demonstrate the system functionality, showing performance similar to the simulations. The implementation of the proposed systems with integrated technologies could reduce the system SWaP and increase robustness to vibrations. A design based on the consolidated SOI platform with the transfer printing-based hybrid integration of InP semiconductor optical amplifiers is proposed. The amplifiers compensate for the losses of the passive SOI waveguides, decreasing the overall conversion loss. The polarization multiplexing of the modulated and unmodulated combs to be sent from (to) the primary to (from) the secondary satellite over the FSO links avoids complex space-consuming optical filters requiring several control signals.

Low Power Consumption Hybrid-Integrated Thermo-Optic Switch with Polymer Cladding and Silica Waveguide Core

Taking advantage of the large thermo-optical coefficient of polymer materials, a hybrid-integrated thermo-optic switch was designed and simulated. It is also compatible with the existing silica-based planar light-wave circuit (PLC) platform. To further reduce the power consumption, we introduced the air trench structure and optimized the structural parameters of the heating region. This scheme is beneficial to solving the problem of the large driving power of silica-based thermo-optic switches at this stage. Compared with the switching power of all-silica devices, the power consumption can be reduced from 116.11 mW (TE) and 114.86 mW (TM) to 5.49 mW (TE) and 5.96 mW (TM), which is close to the driving power of the reported switches adopting polymer material as the core. For the TE mode, the switch's rise and fall times were 121 µs and 329 µs. For the TM mode, the switch times were simulated to be 118 µs (rise) and 329 µs (fall). This device can be applied to hybrid integration fields such as array switches and reconfigurable add/drop multiplexing (ROADM) technology.

LDM-satellite: A new scheme for packet loss classification over LEO satellite network

The packet loss classification has always been a hot and difficult issue in TCP congestion control research. Compared with the terrestrial network, the probability of packet loss in LEO satellite network increases dramatically. What's more, the problem of concept drifting is also more serious, which greatly affects the accuracy of the loss classification model. In this paper, we propose a new loss classification scheme based on concept drift detection and hybrid integration learning for LEO satellite networks, named LDM-Satellite, which consists of three modules: concept drift detection, lost packet cache and hybrid integration classification. As far, this is the first paper to consider the influence of concept drift on the loss classification model in satellite networks. We also innovatively use multiple base classifiers and a naive Bayes classifier as the final hybrid classifier. And a new weight algorithm for these classifiers is given. In ns-2 simulation, LDM-Satellite has a better AUC (0.9885) than the single-model machine learning classification algorithms. The accuracy of loss classification even exceeds 98%, higher than traditional TCP protocols. Moreover, compared with the existing protocols used for satellite networks, LDM-Satellite not only improves the throughput rate but also has good fairness.

On-Chip Quantum Communication Devices

We present here results of the Quantum Technology Flagship project UNIQORN in the area of integrated photonics for quantum communication applications. Three distinct integration platforms, namely indium phosphide based monolithic integration, polymer-based hybrid integration and the CMOS-compatible silicon platform, have been employed to manufacture components and sub-systems on chip for quantum communication devices. The choice of different platforms was made to exploit the best characteristics of each platform for the intended quantum communication device. The indium phosphide platform was employed to manufacture a transmitter chip for quantum key distribution featuring laser, modulators, and attenuators. The transmitter chip was evaluated in a QKD experiment achieving a secure rate of 1 kbit/s. The polymer platform was investigated for engineering non-classical light sources. Entangled and heralded single-photon sources, based on non-linear optics, were assembled on the polymer in a hybrid fashion together with waveguides and other passive micro-optical elements. A quantum random number generator, featuring a 70% randomness extraction efficiency, was also fabricated using the polymer integration technique. An array of 32 individual single-photon avalanche diodes, operating at room temperature and featuring an onboard coincidence logic, was coupled to the chip to demonstrate direct detection of photons on the polymer. Finally, a transimpedance amplifier based on gallium arsenide high electron mobility transistors was produced with an exceptional large electrical noise clearance of 28 dB at 100 MHz.

Printable and flexible photodetectors via scalable fabrication for reading applications

Printing techniques have been widely adopted in the fabrication of flexible electronic components. However, its application is still limited in complex control and communication circuitry due to the low performance and low fabrication uniformity amongst printed devices, compared to conventional electronics. Thus, the electronic systems in real-world applications are hybrid integrations of printed and conventional electronics. Here we demonstrate a low-cost, low-complexity, fully-printable flexible photodetector that can withstand over 100 1 mm-radius bending cycles using a simple and scalable two-step fabrication process. The prototypes are implemented in an augmented book system to automatically detect the ambient light through optical apertures on paper of a printed book, and then transmit the information to an adjunct device. This technique demonstrates the utility of low-cost materials and processes for robust large area sensing applications and could act as a gateway to pertinent multimedia information.

HINOTORI and Maser Observations

AbstractHINOTORI (Hybrid Integration Project in Nobeyama, Triple-band Oriented) has constructed a higher sensitivity 22/43 GHz and a 22/43/86 GHz simultaneous observation systems in the Nobeyama 45-m telescope by introducing new frequency separation filters in the telescope’s quasi-optics. The performance of the observation systems, such as the beam squint, the aperture efficiency, the system noise temperature when inserting the filters, and the phase stability of the signal path have been evaluated. It is indicated that the established systems have sufficient performance for single-dish and VLBI observations. The single-dish observation demonstrations using the triple-band system were successfully conducted in acquiring scientific data including multiple maser lines.

Integrated passive nonlinear optical isolators

Fibre and bulk optical isolators are widely used to stabilize laser cavities by preventing unwanted feedback. However, their integrated counterparts have been slow to be adopted. Although several strategies for on-chip optical isolation have been realized, these rely on either integration of magneto-optic materials or high-frequency modulation with acousto-optic or electro-optic modulators. Here we demonstrate an integrated approach for passively isolating a continuous-wave laser using the intrinsically non-reciprocal Kerr nonlinearity in ring resonators. Using silicon nitride as a model platform, we achieve single ring isolation of 17–23 dB with 1.8–5.5-dB insertion loss, and a cascaded ring isolation of 35 dB with 5-dB insertion loss. Employing these devices, we demonstrate hybrid integration and isolation with a semiconductor laser chip. The intrinsic Kerr nonlinearity in ring resonators is exploited to demonstrate passive isolation of a continuous-wave laser. Up to 35-dB isolation with 5-dB insertion loss was achieved on-chip.

Memtransistor-Based Ternary Content-Addressable Memories: Design and Evaluation

The memtransistor (MT) based on 2-D materials is considered a promising candidate to extend Moore’s law, thanks to its scalability. As a hybrid integration of a memristor and a transistor, MT combines the electrical properties of memristor-based one-transistor one-resistor (1T-1R) structures (i.e., nonvolatile resistive switching and gate selection) into a single compact device. In this work, we evaluate MT technology from an application perspective and explore its use in ternary content-addressable memory (TCAM) systems. Based on characterization data from a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${10} \times {10}$ </tex-math></inline-formula> MoS2-based MT crossbar array, we propose two designs of MT-based TCAM (i.e., bitcells and TCAM array implementations and layouts). We also explore the design space of TCAM parameters and compare the performance and reliability of the proposed TCAM designs. In particular, we demonstrate that the use of MT technology facilitates the implementation of long TCAM words (>2 kbits) at low MT resistance ratios and search voltages, which is desirable for long TCAM endurance.

Hybrid integration of chipscale photonic devices using accurate transfer printing methods

Transfer printing is becoming widely adopted as a back-end process for the hybrid integration of photonic and electronic devices. Integration of membrane components, with micrometer-scale footprints and sub-micron waveguide dimensions, imposes strict performance requirements on the process. In this review, we present an overview of transfer printing for integrated photonics applications, covering materials and fabrication process considerations, methods for efficient optical coupling, and high-accuracy inter-layer alignment. We present state-of-the-art integration demonstrations covering optical sources and detectors, quantum emitters, sensors, and opto-mechanical devices. Finally, we look toward future developments in the technology that will be required for dense multi-materials integration at wafer scales.

Droplet‐Based Electricity Generator toward Practicality: Configuration, Optimization, and Hybrid Integration

AbstractElectricity is the basic and essential need for every single person and guarantees the development of society, industry, and the economy. The limited conventional fossil fuel meets the challenge of the sharply increasing demand, while may lead to severe pollution. Emerging green energy harvesting systems can convert ambient kinetic, thermal, and solar energy to electricity effectivity. In this review paper, the authors provide an overview of the new and emerging methods, droplet‐based electricity generators, that convert energy from the ubiquitously existing water droplets. The authors begin with a brief introduction of the working principle for droplet‐based power generators. Existing configurations of the droplet‐based power generator are also summarized, including 1) single electrode, 2) transistor‐based, and 3) direct current generator. Then, a detailed discussion of the design and operation factors that may impact the energy harvesting efficiency of droplet‐based power generators is provided. Hybrid energy harvester that integrates droplet‐based power generators with other triboelectric, pyroelectric, and photovoltaic‐based devices are summarized. Finally, challenges and perspectives regarding the future development of droplet‐based power generators are described. The reviews demonstrate a highly efficient method for energy harvesting from water droplets to meet the vital needs of the energy crisis.

Design of Monolithic 2D Optical Phased Arrays Heterogeneously Integrated with On-Chip Laser Arrays Based on SOI Photonic Platform.

In this work, heterogeneous integration of both two-dimensional (2D) optical phased arrays (OPAs) and on-chip laser arrays based on a silicon photonic platform is proposed. The tunable multi-quantum-well (MQW) laser arrays, active switching/shifting arrays, and grating antenna arrays are used in the OPA module to realize 2D spatial beam scanning. The 2D OPA chip is composed of four main parts: (1) tunable MQW laser array emitting light signals in the range of 1480-1600 nm wavelengths; (2) electro-optic (EO) switch array for selecting the desired signal light from the on-chip laser array; (3) EO phase-shifter array for holding a fixed phase difference for the uniform amplitude of specific optical signal; and (4) Bragg waveguide grating antenna array for controlling beamforming. By optimizing the overall performances of the 2D OPA chip, a large steering range of 88.4° × 18° is realized by tuning both the phase and the wavelength for each antenna. In contrast to the traditional thermo-optic LIDAR chip with an external light source, the overall footprint of the 2D OPA chip can be limited to 8 mm × 3 mm, and the modulation rate can be 2.5 ps. The ultra-compact 2D OPA assembling with on-chip tunable laser arrays using hybrid integration could result in the application of a high-density, high-speed, and high-precision lidar system in the future.

Hybrid-Integrated Comb Source With 16 Wavelengths

Comb sources and multi-wavelength lasers can be used as central sources of light in many communication systems using high channel count wavelength division multiplexing. Here, we demonstrate a 16 wavelengths comb source built through large scale hybrid integration of 16 active gain chips with a passive silica chip that incorporates a 16 channel arrayed waveguide grating. Optical coupling between the 16 gain chips and the silica chip is achieved through 32 ball lenses (two per channel), that are aligned and attached in place with an automated process that we developed. The 16 channels have 100 GHz spacing and are centered in the C-band. We show monomode lasing, both in single-channel and multi-channel operation, with side mode suppression ratio as high as, respectively, 67 dB and 55 dB. The total output power of our comb source is about 17.9 dBm when all the 16 channels are activated simultaneously. The channels of our multi-wavelength laser have very narrow Lorentzian linewidths, with best value as narrow as 880 Hz and worst value of about 3.6 kHz. Our comb source integrates hybridly a large number of optical components, however thanks to the parallel architecture and the possibility of packaging the lenses with an automated process, our integration approach can be scaled to an even higher number of channels.

Graphene–Silicon Hybrid MOSFET Integrated Circuits for High-Linearity Analog Amplification

To overcome the nonlinear distortion inherent in analog ICs based on Si-MOSFETs, we report here the graphene-silicon hybrid analog amplifier ICs that integrate graphene field-effect transistor (GFET) and Si-MOSFET components. By fabricating homogeneous GFETs on a silicon wafer with prefabricated Si-MOSFETs, we obtained the hybrid ICs that neatly incorporate the high linearity of GFETs. The high-linearity analog amplifier ICs can thus be realized simply using basic MOSFET circuit configurations, without requiring complicated calibration designs. This hybrid integration principle may enable immediate practical applications of graphene electronics.

Reliability analysis with correlated random variables based on a novel transformation, adaptive dimension-reduction and maximum entropy method

In this paper, structural reliability analysis including correlated random variables is implemented based on a novel transformation and fractional exponential moments-based maximum entropy method (FEM-MEM) with a new adaptive dimension reduction. First, a novel transformation, which does not require the computation of correlation matrix in correlated standard normal space, is first presented to transform correlated random variables to be independent standard normal ones, which is quite easy and simple to implement. Then, an adaptive dimension-reduction model is developed for efficient FEMs estimation, where the contribution-degree analysis is performed and a hybrid integration formula is established accordingly. Further, the FEM-MEM, in which the proposed transformation and hybrid integration formula are embedded, is applied to derive the unknown probability distribution of the performance function with correlated random variables, which overcomes the shortcomings of traditional fractional moments-based MEM and significantly enhances the robustness, accuracy and efficiency. Four numerical examples including both the explicit and practical implicit performance functions are investigated to validate the proposed method, where pertinent Monte Carlo simulation and Nataf transformation are employed for comparisons.

Wafer-Scale Fabrication of Silicon Film on Lithium Niobate on Insulator (LNOI)

Hybrid integration of silicon photonics with lithium niobate (LN) devices provides a promising route to enable an excellent modulation performance in silicon photonic integrated circuits. To realize this purpose, a substrate containing a Si film on an LNOI substrate, called Si on the LNOI structure, was analyzed and fabricated. The mode propagation properties in the Si-on-LNOI structure were simulated in detail and a vertical adiabatic coupler (VAC) between the Si waveguide and LN waveguide was simulated to help in the determination of the dimension of this structure. A 4-inch wafer-scale Si on an LNOI hybrid structure was fabricated through the ion-cut process. This structure has a single-crystalline quality, high thickness uniformity, smooth surface, and sharp bonding interface, which are practical for realizing low loss and high coupling efficiency.

Transfer-printing-based integration of silicon nitride grating structure on single-crystal diamond toward sensitive magnetometers

Negatively charged nitrogen-vacancy (NV) centers in diamond have emerged as promising candidates for a wide range of quantum applications, especially quantum sensing of magnetic field. Implementation of nanostructure into diamond is powerful for efficient photon collection of NV centers and chip-scale miniaturization of the device, which is crucial for sensitive and practical diamond magnetometers. However, fabrication of the diamond nanostructure involves technical limitations and can degrade the spin coherence of the NV centers. In this study, we demonstrate the hybrid integration of a silicon nitride grating structure on a single-crystal diamond by utilizing transfer printing. This approach allows the implementation of the nanostructure in diamond using a simple pick-and-place assembly, facilitating diamond-based quantum applications without any complicated diamond nanofabrication. We observed the intensity enhancement in the collected NV emissions both theoretically and experimentally using the integrated grating structure. By applying the increased photon intensity, we demonstrate the improved magnetic sensitivity of the fabricated device. The proposed hybrid integration approach will offer a promising route toward a compact and sensitive diamond NV-based magnetometer.

New low order Runge–Kutta schemes for asymptotically exact global error estimation of embedded methods without order reduction

Embedded Runge–Kutta (RK) methods provide an attractive methodology for solution of initial value problems (IVP) by means of adaptive step size control. According to Fehlbergs suggestion, only one extra function calculation is required to estimate the local error of the embedded method. In the present paper, this methodology is applied to three prominent low order implicit RK-schemes. To this end, new embedded Butcher-tableaus are presented for the implicit Euler-method, the trapezoidal-rule and the midpoint-rule by means of corresponding higher order RK-schemes. In order to account for the global error, an asymptotically exact global error estimator is derived for the so-called reversed embedded RK-method. Moreover, a cause of order reduction is illustrated by aid of a weak discontinuous formulation. It is prevented in a new hybrid integration algorithm by means of a Hermite interpolation for the source term of the IVP, and its implementation renders a convenient “node-to-node” stepping scheme for a laser beam simulation. Two numerical examples are presented with the following main results: The higher order convergence behaviors of the proposed new RK-schemes are verified, its successful performances for asymptotically exact global error estimation of the reversed embedded RK-method are shown, the proposed methodology is illustrated for two different global error functions, and the desired effect of the hybrid algorithm to prevent order reduction is illustrated.