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In this work, we present an advanced heterogeneous integration scheme which consists in integrating a thin InP layer by wafer-bonding onto a silicon wafer (InPoSi) on which a regrowth step of III-V materials is implemented. Vertical p-i-n AlGaInAs lasers obtained from a single Selective Area Growth (SAG) step on InPoSi were fabricated. Thanks to SAG, the AlGaInAs-MQW structures successfully cover a PL range of 160 nm in the C+L band. Based on these structures, a 5- channel laser array was fabricated. The latter successfully covers a 155 nm-wide spectral band from 1515 nm to 1670 nm with a maximum output power of 20 mW under continuous-wave regime at 20°C. High thermal stability up to 70°C is demonstrated with a characteristic temperature of 69°C for the lasers emitting from 1515 nm to 1600 nm.

In the frame of the H2020 PICTURE project, we designed and developed densely integrated photonic devices and transceiver (TRx) circuits for high bit-rate telecom and datacom applications. We implemented a process with four different InP-based dies bonded on SOI wafers. With one sole back-end processing run, we achieved the fabrication of multiple components of the complex TRx circuits, and many building block devices, such as III-V/Si SOAs & Fabry-Perot lasers, photodiodes or fast tunable capacitive DFB lasers. First testing of these devices shows promising results. 13dBm-saturation power SOAs and less than 2ns-tuning time capacitive DFB lasers were fabricated and demonstrated.

Vertical p-i-n lasers integrated by wafer-bonding and regrowth on a heterogeneous InP-on-SOI wafer are presented. We demonstrate for the first time lasers based on regrown III-V active regions efficiently coupled to Si-photonic DBR cavities.

Optical phased arrays (OPAs) with the ability of dynamic beam-steering hold great promise for industrial applications. Although they potentially offer high-resolution, high-speed and wide-angle beam-steering, 2D beam-steering has only been achieved by 1D OPAs with wavelength-tuning or by 2D OPAs containing enormous numbers of elements, thereby significantly increasing the system complexity and power consumption. Here we demonstrate a liquid-crystal-tunable Bragg-reflector waveguide outcoupler integrated with a 1D OPA. The output beam angle is controlled by an electric-field applied to the liquid crystal between the Bragg-mirrors, independently from steering along a second axis with the OPA. Our proof-of-concept demonstration with an 8-channel OPA shows 2D beam-steering with a 16° × 15° field-of-view and 12 ms × 14 μs time-response. Our approach opens a practical way for scalable OPAs capable of single wavelength 2D beam-steering, as well as demonstrating a strategy for the integration of liquid crystal materials with silicon photonics.

Progresses in Photonic Integrated Circuits (PICs) demand development of high performance photonic devices, including phase modulators. Capacitive phase modulators present high efficiency and low consumption, at the cost of technical challenges for their integration in PICs. A 200mm wafer process flow for thin gate oxide employed for MOSCAP modulators fabrication is presented here.

Epitaxial growth of high material quality $1.55\boldsymbol{\mu} \mathbf{m}$ AlGaInAs Multiquantum Wells Heterostructure on a directly-bonded InPoSi substrate has been developed for datacom applications.

We demonstrated a wide wavelength-tuning range of $90\ nm$ with a hybrid InP/SOI laser, based on two integrated intracavity silicon ring resonators which produce a Vernier effect, and a low losses silicon cavity delimited by broadband Sagnac mirrors.

This paper describes a high quality factor III-V on silicon hybrid laser consisting in a harmonic optical potential well cavity. We measured a photon lifetime as high as 103 ps and a relative intensity noise below 147 dB/Hz with a constant level over 20 GHz.

We report on the experimental characterization, in the telecom C-band, of group-velocity dispersion (D) in 100-nm high rectangular strip waveguides realized by silicon-on-insulator technology. We compare the experimental results with numerical predictions, showing that 100-nm high waveguides exhibit normal dispersion and that the absolute value of the dispersion coefficient D decreases as the waveguide width is increased. D at 1550 nm varies from −8130 to −3900 ps/(nm·km) by increasing the waveguide width from 500 to 800 nm.

Optical resonators are fundamental building-blocks for the development of Si-photonics-integrated circuits, as tunable on-chip optical filters. In addition to the specific spectral shape, which may vary according to a particular application, extremely low losses from these devices are a crucial requirement. In the current state-of-the-art devices, most low-loss filters have only been demonstrated by exploiting ad hoc lithographic and etching techniques, which are not compatible with the standard CMOS (complementary metal-oxide semiconductor) process-flow available at Si-photonic foundries. In this paper, we describe the design and optimization of optical micro-resonators, based on Si-waveguides with a height lower than the standard ones (i.e., less than 220 nm), prepared on SOI (silicon on insulator) platform, which allow the realization of high-performance optical filters with an insertion loss lower than 1 dB, using only previously validated lithographic etch-depths.

International audience; We report about the final results of the FABULOUS European project, demonstrating the feasibility of real-time Ethernet transmission on a self-coherent reflective passive optical network, using an optical network unit (ONU) whose main optical functions are performed by a silicon-photonics device; 500 Mbps per user with a power budget of 24 dB in offline processing and 21 dB in real time is shown. We also report details about the packaging process and the special technique developed for the flip-chipping of a CMOS electrical driver, used for driving the ONU with low voltage, onto a silicon Mach-Zehnder modulator.

Novel processes were developed for fabricating silicon nanocrystals and nanocomposite materials which could be used as absorbers in third generation photovoltaic devices. A conventional high-temperature annealing technique was studied as a reference process, with some new insights in crystallisation mechanisms. Innovative methods for silicon nanocrystal synthesis at much lower temperature were demonstrated, namely chemical vapour deposition (CVD), physical vapour deposition (PVD) and aerosol-assisted CVD. Besides the advantage of low substrate temperature, these new techniques allow to fabricate silicon nanocrystals embedded in wide bandgap semiconductor host matrices, with a high density and a narrow size dispersion.

Thanks to their outstanding electrical properties [1,2], carbon nanotubes (CNTs) are promising candidate to replace Cu in advanced interconnects [3-8]. In damascene based CNT via integration scheme, CNTs growth occurs on the whole surface of the wafers: in vias, but also on top surfaces [5]. CNTs on top are subsequently removed by polishing. In this paper, an alternative integration scheme is proposed which avoids CNTs on top. Thanks to careful choice of top surface (TiN) and bottom electrode (doped silicon) materials, CNT growth occurs only in vias. Dense growth (6x10^1^1CNTs/cm^2) of small multi wall CNTs is achieved in vias over doped poly-silicon lines. Good encapsulation of CNTs is obtained with SACVD SiO"2 or ALD Al"2O"3 materials. Thanks to polishing of emerging CNTs, planarized CNT vias are obtained. Initial electrical measurements by conductive AFM show the conductivity of these CNT vias.

We have succeeded in direct integration of carbon nanotubes (CNTs) for via interconnects using different back contact materials. Highly doped Si and poly Si are used, aiming at the CNT via interconnects directly from source, drain and gate of transistors. In addition, we propose to use aluminum copper alloy (AlCu) as a metal line because of its higher conductivity compared that of copper in very small geometries. The experimental conditions for CNT growth are optimized on these three substrate materials, which are applied for the direct integration in via holes with success. The achieved density in 1 μm via holes is more than 10 12 cm − 2 , the highest value reported so far.

Our laboratory is involved in the French EUV (Extreme Ultra-Violet) program PREUVE to develop Mo/Si mirrors for blanks free of defects by using an ion beam sputtering deposition technique. This paper illustrates a reduction strategy used to lead to an EUV mirror with a defect density as low as possible. One of the methods adopted is the analysis of the process step by step, therefore, the defect number added by each process step has been quantified. It appears that the most critical step is substrate cleanness. Today, our best performance for a final mirror is 1.2 def/cm 2 with a defect size >200 nm. This value has been measured on our home-made counting device COMNET. Our counting device has been validated by comparison with a commercial tool. Two improvements have been implemented on COMNET to increase its routine performance which allows to detect particles of 200 nm. The first one is the sample illumination with a laser in oblique incidence (60°) which increases the signal-to-noise ratio. The noise is the roughness of the sample. The second one is the implementation of a cooled CCD camera with a variable exposure time. Thanks to these improvements, the detection of particles with a diameter size of 155 nm has been demonstrated. On the basis of the experimental results and calculations, the detection of 100 nm particles on silicon and EUV blanks can be reasonably predicted.

We investigated the possibility of using physical vapour deposited Ge nanocrystals (NCs) in optoelectronic devices such as solar cells. We have prepared p-i-n heterojunctions based on p+-doped Si substrate/undoped Ge NCs/ZnO:Al layer stacks and their optoelectronic properties were characterised. Under light, the generation of photo-carriers from the Ge NCs themselves was demonstrated. The photovoltaic behaviour of the p-i-n structure was also highlighted, with a measured Voc of 224 mV compared to 580 mV in theory. The discrepancy between theory and experiment was discussed on the basis of TEM observations, optical and carrier generation measurements as well as modelling.

Germanium nanocrystals were prepared by a nanocluster source and characterized by photoluminescence and spectroscopic photometry methods. The optical measurements were carried out in order to estimate the effective bandgap of the Ge nanocrystals. Both Mie theory and the quantum confinement theory were applied to interpret the extracted absorption data. We found that the quantum confinement theory enables to explain the nanocrystal size and the host matrix dependence of the nanocrystal bandgap. On the other hand, the photoluminescence measurements have not allowed to confirm the bandgap evaluated from absorption data. This is explained as due to the dominant effect of the recombination at the nanocrystals surface.

In this study, the synthesis of Ge nanoparticles by a physical vapour deposition (PVD) nanocluster source has been investigated. We typically obtain Ge nanoparticles with a mean diameter between 4 and 9 nm. The microstructure of Ge nanoparticles was widely studied by high resolution transmission electron microscopy, energy filtered transmission electron microscopy, X-ray diffraction and Raman spectroscopy. The main result is the capability of the PVD process to synthesize well crystallized Ge nanocrystals at room temperature and without any post thermal annealing. It was found from Raman analysis that these room temperature deposited nanoparticles are composed of a Ge crystalline core and a sub-nm thick amorphous Ge shell. A low temperature annealing (450 °C) during 1 h under vacuum leads to the reorganization of the surface atoms while longer annealing seems to promote the formation of a Ge oxide shell around the nanoparticles.

One of the most important challenges in extreme ultraviolet lithography is the need to provide mask blanks free of defects. In order to provide experimental results on the printability of buried defects, a dedicated extreme ultraviolet (EUV) mask blank was manufactured using ion beam sputtering (IBS) with a nonsmoothing process. Using this kind of process, the effect of the buried defect is apparent throughout the entire multilayer stack. The disturbance generated in the multilayer, measured using an atomic force microscope (AFM), shows lateral growth and a slight vertical smoothing effect. Here we report the printability results obtained with this kind of defect. One result concerns the influence of the defect density on the printability. We show that the major effect can be attributed to local flare, which depends on the pattern density. In order to better understand the printability mechanism of this kind of buried defect, we also compared the experimental results with electromagnetic simulation.

A technique to probe defects buried inside extreme ultraviolet (EUV) masks has been implemented using a dark-field microscopy detection setup. Specific samples have been fabricated to evaluate the sensitivity of this technique. They consist of silicon oxide gratings of a few nanometers height, coated with 40 layer pairs of molybdenum-silicon. We observed images with a good contrast on samples with defects as low as 3 nm. However, the imaging mechanism of scanning dark-field microscopy is not linear and can produce image distortions. Conditions of correct imaging have been analyzed, and simulations have been performed that show good agreement with the experimental data. This work opens the way for a better understanding of the capability of at-wavelength inspection technique for EUV mask.

In the field of microelectronics, Extreme Ultraviolet (EUV) lithography operating at λ=13,5 nm, appears, today, as the most promising future technology. The viability of this next generation technology has to face, however, several technical issues. Among them, the realisation of defect-free lithography masks is certainly one of the most serious issue. These masks, which work as reflective components, are composed of an EUV reflective Mo/Si multi-layer coating deposited on a glass substrate and covered, on the top, by an absorbing stack. Up to now, as far as defect specification is concerned, Ion Beam Sputtering (IBS) deposition has been proved to be the most appropriate technology. Nevertheless, the necessity to meet other specifications like, for instance, maximum EUV reflectance, requires further studies to better understand the way such IBS multi-layer Mo/Si structures are growing. In this paper, an experimental investigation on the deposition of IBS Mo/Si multi-layers is presented. We focused our interest on a comparison between argon and xenon sputtering conditions. After a brief description of deposition process, the mechanical and optical properties of the films are first reported. Then, the microstructures and chemical profiles of Mo/Si multi-layers, deduced from investigations by high-resolution transmission electron microscopy (HRTEM) and energy filtering TEM, are presented. Finally, the Mo/Si mirror characteristics are discussed on the basis of TEM observations and process considerations related to sputtering mechanisms taking place in the IBS deposition tools.

The characteristics of a defect counting tool, COMNET< based on scattering light measurement, is presented. This prototype supports the development of defect-free EUV blanks. Thanks to new improvements, it becomes possible to detect PSL particles having a diameter as low as 100 nm, with a video CCD camera, on silicon substrates or on EUV blanks. To reach this sensitivity, one of the enhancements consists in a laser irradiation close to 65°. The present configuration and the use of a CCD camera, with a variable exposure time, should lead to the detection of 80 nm PSL particles deposited on silicon substrate. This extrapolation is based on experimental results and on a simple model. To detect 100 nm particle and smaller particles, it is essential to reduce the level of stray light and to increase the signal to noise ratio. In our application, the stray light essentially comes from three sources: the noise induced by the roughness of the sample, the Rayleigh scattering of the atmosphere, and the stray light in the room. The restrictions induced by these phenomena are described in some detail. All the improvements are not only available for the characterization of silicon substrates but also for transparent blank substrates and for EUV mask blanks. The additional noise induced by the tranparent substrate is analyzed. The defects, whatever the compoent sizes and the component shapes can be detected. A cross characterization achieved with a commercial tool on silicon substate is reported. Counting measurements performed on EUV blanks are shown. Furthermore, a more explicit definition of added defects is proposed.

International audience; The stress evolution of IBS-deposited Mo and Si 100-nm-thick films has been investigated. Mo films’ compressive stress decreases from −2550 MPa to −1000 MPa as the sputtering gas changes from Ar to Xe, whereas Si films’ stress remains constant around −850 MPa whatever the sputtering gas. Then the stress behaviour of Mo/Si multilayers sputtered either with Ar or Xe has been observed. In both cases, the multilayer stress first becomes less compressive and then increases, as Mo thickness in the multilayer increases. However, like in the single layer case, the level of stress strongly depends on the sputtering gas. The multilayers sputtered with Xe even become tensile. Moreover, the analysis of the contraction of the multilayers led us to the conclusion that a Mo/Si interface grows, but in a different way, depending on the sputtering gas. Possible stress-generating mechanisms during growth of these multilayers as well as single layer films of Mo and Si are discussed.

As a participant of the French Extreme UltraViolet (EUV) program PREUVE, our laboratory has been involved for one year in the development of Mo/Si blanks free of defects using an Ion Beam Sputtering deposition technique (IBS). Among the different tasks to end at an EUV stepper, the achievement of the blank and its characterization in terms of defect counting is probably one of the most challenging. This is the reason why a characterization tool based on the well known scattering method is under progress in our laboratory. In addition to defect counting, the possibility of cleaning a sample (substrate, blanks,.) with a powerful laser source is allowed on the same facility. This set up is fully computerized. Its first performances are illustrated with several examples on our blanks and silicon substrates. Our system is designed to optimize the laser cleaning parameters (wavelength, incidence, polarization,.) and to decrease the detection limit size. Today, our facility currently enables the detection of the defect as small as 200 nm in size. Our strategy is to reach the defect size as low as possible and at least until 50 nm, which is the size of interest for the EUV lithography. The major developments under consideration in order to lessen the detection limit size are described in details in this paper. Moreover, the roughness of the EUV blanks may be evaluated with our device. This surface parameter has to be optimized, at least for two reasons : to reduce the optical losses and to decrease the number of defects. The mean to quench the roughness signal in order to detect the smallest defect size and the possibility to evaluate the component roughness are combined on the same facility. The major trumps of our experiment are the visualization of the defects in live, the measurement of the defect sizes and the quick evaluation of the laser cleaning efficiency versus various experimental conditions. The cleaning part of the set up is built up to use various powerful laser sources and to shoot, with the laser, only the locations where the defects remain. Finally, this facility allows to evaluate and to optimize our defect free blank process.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The properties of materials in thin films are strongly dependent on the coating techniques and on the technological parameters. We have investigated about some optical and structural properties of YF3 thin films prepared using different energetic techniques: ion assisted deposition (IAD) and ion beam sputtering (IBS). The properties of the thin films obtained by these energetic processes are compared to the properties obtained by classical electron beam evaporation. In classical evaporation, the optical properties in the visible range depend on the temperature of the deposition and on the incidence of the vapor flux. The optical properties are correlated with the density of the films measured by Rutherford backscattering. In the case of IAD, the influence on optical properties, both in the visible and in the infrared range, of some technological parameters (pressure, ion energy and ion density) are illustrated. The refractive index and the extinction coefficient have been obtained by spectrophotometry. Furthermore, we show that IBS may lead to YF3 layers of high density.

In this study, the nodule growth in ion beam sputtering Mo∕Si coatings used for extreme-ultraviolet (EUV) lithography masks has been studied in relation with the number of Mo∕Si pairs (period 7 nm). To trigger this growth, initial particles of different sizes (d=40–155nm) were used. With a deposition angle of 30° and after the deposition of 40–60 Mo∕Si pairs, the lateral size of nodules was found to grow up to ∼2d while its height ranged from d∕6 to d∕2 depending on the initial particle diameter. This lateral growth was demonstrated to mainly result from shadowing effect. Besides, a vertical smoothing effect was evidenced even in the case of relatively large initial seed particles (70–155 nm). It is attributed to adatom surface diffusion which is also thought to promote a slowdown in the nodule lateral growth when increasing the coating thickness. Finally, a real case of mask blank realization is presented showing that a good knowledge of nodule growth is essential to properly analyze the defect character...

Control of silver nanoparticles characteristics using a dedicated nano-clusters source and wavelength tuning of Plasmon resonance generated by small nanoparticles using different matrices. The results have been validated by advanced surface Plasmon modeling. © 2010 Optical Society of America.

Silver nanoparticles have been prepared using a "terminated gas condensation" technique. An unprecedented control of 5-6 nm-size nanoparticles with well defined shape and variable surface densities has been achieved. The technology is shown to permit independent control of both, plasmon resonance intensity and frequency position. On the basis of optical measurements, a smart tuning of plasmon resonance intensity with particle density is indeed demonstrated. Moreover, the embedding of NPs in different surrounding medium enables to control the resonance wavelength as experimentally demonstrated and theoretically confirmed. © (2011) Trans Tech Publications, Switzerland.