We bonded quantum well InP dies on a photonic layer transferred on silicon CMOS processed wafer using direct molecular bonding. This approach is suitable for new applications, viz., photonics on ...silicon, 3D packaging and integrated sensors. The chips are diced from a bulk substrate and bonded directly onto a silicon substrate without any organic nor metallic adhesive layer. A thin silicon dioxide layer can be added on both assembled surfaces to enhance bonding quality. After bonding, the dies can mechanically be thinned down to 20
μm and chemically etched. The InAsP quantum well stack of the InP dies keeps its optoelectronics features and performances after being transferred onto a silicon substrate.
The Smart-Cutregistered trademark process, based on ion implantation (hydrogen, helium) and wafer bonding, appears more and more as a generic process. The first part of the paper is dedicated to the ...specific case of thermally-induced splitting. Cavity growth by the Ostwald ripening mechanism and crack propagation are responsible for thermally-induced splitting. In this case, the splitting kinetics are controlled by hydrogen diffusion. In the second part, the latest results concerning new structures are presented.
The Smart-Cut process used to produce SOI wafers is based on proton implantation and wafer bonding. In this paper, the behavior of the cavities induced by hydrogen implantation in silicon is studied. ...The effect of a bonded stiffener on the splitting mechanism is shown. The quality of bonding depends greatly on the cleaning process which enables a high bonding energy and a high quality material to be achieved.
We report results on hexagonal-shaped microlasers formed from two-dimensional photonic crystals (PCs) using InP-based materials transferred and bonded onto SiO/sub 2// Si wafers. Two types of ...hexagonal cavities are investigated : single defect (one hole missing) cavities, so-called H1 cavities (1 /spl mu/m in diameter) and two holes missing per side H2 cavities (2 /spl mu/m in diameter). Their optical properties are analyzed using photoluminescence experiments, and plane wave method simulations have been performed for comparison. High Q modes (/spl sim/600/700) have been measured and they have been shown to enable laser effect at room temperature, under pulsed optical pumping (15% duty cycle and 25-ns pulsewidth). The study of these efficient mode characteristics gives guidance for further improvement of the operation conditions of PC lasers, such as the reduction of the threshold pumping power.
Ultra thin film of silicon bonded on 4 in. (001) silicon wafers have been obtained by combining a direct hydrophobic silicon bonded technique with a layer transfer. The twist angle between the ultra ...thin Si film and the Si substrate was varied from 0 to 15°. X-ray reflectivity measured the thickness and the roughness of the ultra thin films. Complementary results concerning the interface structure were obtained with high resolution transmission electronic microscopy. It is shown that an ultra thin film (a few nm) can be reproductively prepared upon the full 4 in. wafers. Moreover, this process gives very small thickness fluctuations and a small surface roughness. The bonding interface has a low concentration of oxide precipitates and presents two arrays dislocations respectively, due to the twist (screw dislocations) and a residual tilt angle (mixed dislocations) of the crystals. Dissociation of the screw dislocations is also observed on the lowest twist angle sample.
The SmartCut process was first developed to obtain Si-on-insulator (SOI) materials. Now an industrial process, the main Unibond SOI-structure trends are reported. Many material combinations can be ...achieved by this process, because it appears to enable the generic development of new structures. Several of the new structures combining different materials and different bonding layers are described. These include SiGe and strained-Si films onto an oxidized Si wafer, Si-on-insulating multilayer (SOIM) structures, and InP or 4H-SiC film transfers onto low-cost substrates via metallic or even refractory conductive-film bonding layers. More recently, an original bonding process based on mark patterning, wafer bonding, and layer transfer has been proposed to obtain structures in which the relative crystalline-axis orientations of both the film and the substrate can be controlled accurately. In this case, a SmartCut process that includes a mark-patterning step appears well suited for precise control of axis orientations. A procedure is described to obtain an ultra-thin Si film bonded onto a Si wafer. An example of a pure screw dislocation network achieved by the mark patterning, bonding, and layer transfer process is reported in this paper. The results have important implications for nanostructure development. 20 refs.
Silicon-on-insulator (SOI) material, mainly known for high-temperature and radiation hard niche applications, is now increasingly used for low power and low voltage devices. The new Smart-Cut
® SOI ...process, which appears as a good candidate to reach ULSI criteria, is described. Effects of physical phenomena, such as H-implantation, stiffer bonding quality and wafer cleaning, are presented. Formation mechanisms of the various bonding defects are discussed and related to particles trapped at the interface. The understanding of these mechanisms enabled SOI wafers to be obtained without any macroscopic defect. Thermal dependence of the interface quality revealed by a selective chemical etching is presented. The Smart-Cut
® process leads to the formation of an SOI structure with a high top silicon thickness homogeneity and a surface microroughness comparable with that of the silicon substrate.
We report on 2D photonic crystal InP membrane micro-lasers transferred onto a silicon wafer. Two types of lasers are investigated: microcavities and defect-free structures, exploiting either ...conventional defect modes, or DFB-like modes. Room temperature low threshold laser operation has been performed for low sized devices.
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