An overview is presented of the current state-of-the-art in silicon nanophotonic ring resonators. Basic theory of ring resonators is discussed, and applied to the peculiarities of submicron silicon photonic wire waveguides: the small dimensions and tight bend radii, sensitivity to perturbations and the boundary conditions of the fabrication processes. Theory is compared to quantitative measurements. Finally, several of the more promising applications of silicon ring resonators are discussed: filters and optical delay lines, label-free biosensors, and active rings for efficient modulators and even light sources.

/pdf/silicon-microring-resonators-3fzr4lpxbh.pdf

Silicon microring resonators

Although compound semiconductors like gallium arsenide have a substantial performance advantage over silicon in photovoltaic and optoelectronic applications, these do not outweigh the costly process of growing large, high-quality layers of these materials and transferring them to flexible or transparent substrates for use in devices such as solar cells, night vision cameras and wireless communication systems. But now John Rogers and his team demonstrate a new fabrication approach that may remove this disadvantage. They grow films of GaAs and AlGaAs in thick, multilayered assemblies in a single deposition sequence, then release the individual layers and distribute them over foreign substrates by printing. The technological potential of this strategy to large-area applications is illustrated with the fabrication of GaAs devices such as field-effect transistors on glass and photovoltaic modules on sheets of plastic. Although compound semiconductors like gallium arsenide (GaAs) offer advantages over silicon for photovoltaic and optoelectronic applications, these do not outweigh the costly process of growing large layers of these materials and transferring them to appropriate substrates. However, a new fabrication approach is now demonstrated: films of GaAs and AlGaAs are grown in thick, multilayered assemblies in a single sequence; the individual layers are then released and distributed over foreign substrates by printing. Compound semiconductors like gallium arsenide (GaAs) provide advantages over silicon for many applications, owing to their direct bandgaps and high electron mobilities. Examples range from efficient photovoltaic devices1,2 to radio-frequency electronics3,4 and most forms of optoelectronics5,6. However, growing large, high quality wafers of these materials, and intimately integrating them on silicon or amorphous substrates (such as glass or plastic) is expensive, which restricts their use. Here we describe materials and fabrication concepts that address many of these challenges, through the use of films of GaAs or AlGaAs grown in thick, multilayer epitaxial assemblies, then separated from each other and distributed on foreign substrates by printing. This method yields large quantities of high quality semiconductor material capable of device integration in large area formats, in a manner that also allows the wafer to be reused for additional growths. We demonstrate some capabilities of this approach with three different applications: GaAs-based metal semiconductor field effect transistors and logic gates on plates of glass, near-infrared imaging devices on wafers of silicon, and photovoltaic modules on sheets of plastic. These results illustrate the implementation of compound semiconductors such as GaAs in applications whose cost structures, formats, area coverages or modes of use are incompatible with conventional growth or integration strategies.

/pdf/gaas-photovoltaics-and-optoelectronics-using-releasable-qyjol0wmrd.pdf

GaAs photovoltaics and optoelectronics using releasable multilayer epitaxial assemblies

Ultra-small, low-power, all-optical switching and memory elements, such as all-optical flip-flops, as well as photonic integrated circuits of many such elements, are in great demand for all-optical signal buffering, switching and processing. Silicon-on-insulator is considered to be a promising platform to accommodate such photonic circuits in large-scale configurations. Through heterogeneous integration of InP membranes onto silicon-on-insulator, a single microdisk laser with a diameter of 7.5 µm, coupled to a silicon-on-insulator wire waveguide, is demonstrated here as an all-optical flip-flop working in a continuous-wave regime with an electrical power consumption of a few milliwatts, allowing switching in 60 ps with 1.8 fJ optical energy. The total power consumption and the device size are, to the best of our knowledge, the smallest reported to date at telecom wavelengths. This is also the only electrically pumped, all-optical flip-flop on silicon built upon complementary metal-oxide semiconductor technology. Scientists demonstrate that a single 7.5-μm-diameter microdisk laser coupled to a silicon-on-insulator wire waveguide can work as an all-optical flip-flop memory. Under a continuous bias of 3.5 mA, flip-flop operation is demonstrated using optical triggering pulses of 1.8 fJ and with a switching time of 60 ps. This device is attractive for on-chip all-optical signal buffering, switching, and processing.

/pdf/an-ultra-small-low-power-all-optical-flip-flop-memory-on-a-2cd934u7jl.pdf

An ultra-small, low power all-optical flip-flop memory on a silicon chip

Monolithic integration of III-V compound semiconductors on silicon is highly sought after for high-speed, low-power-consumption silicon photonics and low-cost, light-weight photovoltaics. Here we present a GaAs/Si direct fusion bonding technique to provide highly conductive and transparent heterojunctions by heterointerfacial band engineering in relation to doping concentrations. Metal- and oxide-free GaAs/Si ohmic heterojunctions have been formed at 300°C; sufficiently low to inhibit active material degradation. We have demonstrated 1.3 μm InAs/GaAs quantum dot lasers on Si substrates with the lowest threshold current density of any laser on Si to date, and AlGaAs/Si dual-junction solar cells, by p-GaAs/p-Si and p-GaAs/n-Si bonding, respectively. Our direct semiconductor bonding technique opens up a new pathway for realizing ultrahigh efficiency multijunction solar cells with ideal bandgap combinations that are free from lattice-match restrictions required in conventional heteroepitaxy, as well as enabling the creation of novel high performance and practical optoelectronic devices by III-V/Si hybrid integration.

/pdf/iii-v-si-hybrid-photonic-devices-by-direct-fusion-bonding-581f3r6ict.pdf

III-V/Si hybrid photonic devices by direct fusion bonding

A review of recent progress in hybrid integrated platforms for silicon photonics is presented. Integration of III-V semiconductors onto silicon-on-insulator substrates based on two different bonding techniques is compared, one comprising only inorganic materials, the other technique using an organic bonding agent. Issues such as bonding process and mechanism, bonding strength, uniformity, wafer surface requirement, and stress distribution are studied in detail. The application in silicon photonics to realize high-performance active and passive photonic devices on low-cost silicon wafers is discussed. Hybrid integration is believed to be a promising technology in a variety of applications of silicon photonics.

/pdf/hybrid-integrated-platforms-for-silicon-photonics-3xl0pukxus.pdf

Hybrid Integrated Platforms for Silicon Photonics

https://biblio.ugent.be/publication/389064/file/584826.pdf

III-V/Si photonics by die-to-wafer bonding

An automatic high-precision layer cutting device for separating a layer from a semiconductor substrate. The cutting device includes a fixed positioning member for receiving at least a portion of a semiconductor substrate that has a weakened area therein and a peripheral annular notch that is located below the weakened area. The positioning member maintains a predetermined position of the substrate on a support. The device also includes cutting means having at least one blade for contacting the substrate and for inducing a cleaving wave into the substrate. The cutting means is operatively associated with the positioning member so that the at least one blade contacts the annular notch and the positioning member prevents movement of the substrate. The at least one blade induces a cleaving wave of sufficient intensity to both divide the substrate at the notch into first and second parts and detach the layer from the substrate along the weakened area.

Substrate layer cutting device and method

The invention relates to a device (40) for automatic high-precision cutting of a layer of material joined to a substrate source by means of an embrittled area, said source substrate and layer forming a set which is to be cut and said device comprising cutting means (531, 532) in addition to means (510) for maintaining the position of the set which is to be cut, characterized in that the cutting means comprise a blade which acts upon the set which is to be cut. The invention also relates to a method for using said device.

Substrate- layer cutting device and method associated therewith

The invention relates to a method for producing a semiconductor structure comprising a superficial layer (20'), at least one embedded layer (36, 46), and a support (30), which method comprises: a step of forming, on a first support, patterns (23) in a first material, a step of forming a semiconductor layer, between and on said patterns, a step of assembling said semiconductor layer with a second support (30).

Method for producing partial SOI structures comprising zones connecting a superficial layer and a substrate

http://ma.ecsdl.org/content/MA2005-01/11/518.full.pdf

Chrystelle Lagahe-Blanchard

Papers

III-V/Si photonics by die-to-wafer bonding

Substrate layer cutting device and method

Substrate- layer cutting device and method associated therewith

Method for producing partial SOI structures comprising zones connecting a superficial layer and a substrate

Recent Results on Advanced Molecular Wafer Bonding Technology for 3D Integration on Silicon