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For silicon photonics, specifically chip-level optical interconnects, an ultrahigh-speed low-energy-consuming laser that can be integrated onto a silicon (Si) wafer is an ideal element. Here, we report on a hybrid Si-on-chip micro-cavity laser structure with a potential of providing such characteristics. As shown in Fig. 1a, the laser structure is a vertical cavity, consisting of a high contrast grating...
A technique to fabricate a vacuum cold-cathode nanoelectronic diode with a remarkably low 2-V turn-on voltage was recently presented. A three-terminal device based on the same technology is here designed and fabricated, to implement a vacuum nano-triode. The attempt was partially successful as the excessively large gate radius does not allow effective current control. Nonetheless, the obtained experimental...
Advanced packaging technology plays more and more important role for device miniaturization, system integration, and performance enhancement. Among many new packaging technologies, fan-out wafer level packaging (FOWLP) aroused more interests and showed the advantages of higher number of I/Os, integration flexibilities, low cost, and small form factor due to the elimination of substrate. However, FOWLP...
As power demands for microelectronic devices continue to rise, new techniques for heat dissipation require innovative fabrication solutions such as on-chip cooling methods. The mechanical reliability of these high-powered, high-pressure systems is particularly sensitive to the interfacial strengths within the microelectronic architectures. In research at Georgia Tech, on-chip cooling methodologies...
Wafer-level thermocompression bonding (TCB) using aluminum (Al) is presented as a hermetic sealing method for MEMS. The process is a CMOS compatible alternative to TCB using metals like gold (Au) and copper (Cu), which are problematic with respect to cross contamination in labs. Au and Cu are commonly used for TCB and the oxidation of these metals is limited (Au) or easily controlled (Cu). However,...
A novel piezoresistive sensitive structure for micromachined high-pressure sensors is proposed. This structure employs several small cavities in a silicon bulk. When high pressure applied on all faces of the bulk, stress emerges between two cavities. The calculation for the variation of the resistance caused by stress in three-dimensional (3D) structure was discussed. According to 3D piezoresistive...
This paper presents a novel, versatile process for the fabrication of wide and deep cavities for silicon MEMS devices without the need for wafer bonding. Instead of filling large trenches with sacrificial materials before encapsulation or directly using wafer bonding, we present a method that utilizes isotropic etching with XeF2 gas through a thin silicon dioxide film prior to the deposition of encapsulation...
In this paper we study the mathematical modelling of a domestic microwave oven with incorporated metallic bars. These bars act like antennas. They are powered by the microwave energy that excites the oven and transmit the energy to the surface of the lossy load (see figure 1). The calculation of the field inside the cavity and of the external characteristics of the cavity as seen by the source guide...
In this paper we study the transmittance and the emission response of two different macroporous silicon structures with cavities. The aim is to evaluate the viability of these structures to be employed in a future gas sensor device.
In this study we compare the optical response of macroporous silicon photonic crystals with several cavities inside their structure respect to the obtained in the single cavity case. We show that there are as much raising peaks in the transmission spectrum as number of cavities are inserted in the middle of the structure. Even more, this study reports the enhancement in the peaks' features -e.g. base...
This paper presents an air-cavity-fed four-element slot antenna array, which is fabricated using a modified silicon micromachining process. Different from traditional silicon micromachining process, the silicon dielectric is fully plated with gold without any silicon being exposed to the electromagnetic environment. In this modified silicon micromachining process, air cavities can be easily obtained...
In this article, we have theoretically proposed and numerically analysed a resonant wavelength tunable Fabry Perot (FP) filter without changing the physical length of the cavity in the mid-infrared range. The proposed FP filter consists of a multilayer cavity, which is constructed by alternately repeating two different sub-wavelength dielectric or semiconductor materials. Such a multilayer structure...
Crack and dislocation of direct wafer bonded silicon diaphragm on silicon dioxide layer of silicon substrate containing cavity were analyzed. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and focused ion beam (FIB) were conducted on cracked silicon diaphragm to understand the mechanisms of crack initiation and propagation. SEM analysis results show that the crack initiated...
For the realization of the IoT (Internet of Things) society where the arrival is strongly predicted soon, the construction of an intelligent sensor network is important. For such a sensor network construction, the enormous numerical fusion devices that CMOS devices and MEMS sensors are integrated are essential. To develop WLCSP (Wafer Level Chip Size Packaging) technologies as high density packaging...
In this study, it is shown that temporary tacking (without flux and temporary tack materials) is feasible to temporary tack Cu/SnAg or SnAg sealing ring onto Cu sealing ring at the bottom wafer. The temporary tacked samples were reflowed in a formic acid environment and this allowed the removal of the native oxide of solder. The removal of oxide provides a good solder joints formation during reflow...
We first propose a two-dimensional photonic crystal platform for optomechanically modulating the spontaneous emission. The platform consists of two slotted photonic crystal cavities for optomechanical pumping and emission enhancement respectively, where there is a shared barrier oscillator to bridge the optomechanical dynamics of these two cavities.
Traditional low-refraction-index devices are usually supported by a pedestals, introducing an extra air layer compared with real on-chip devices, which cannot meet the demand of optical interconnection. In this work, we proposed and experimentally demonstrated silica microtoroids bonded on high-refractive-index silicon substrate realizing good light confinement [1]. With proper microtoroid minor diameter,...
Dual MSM PDs based on Transparent Conductive Oxides (TCO) and Au have been fabricated on Si and InP. The devices are designed to detect multiple wavelengths and can be integrated with VCSELs to form optical triplexers for communication systems.
The integration of a photonic information processing system onto a single chip requires great research effort toward engineering metamaterials for miniaturization of the optical devices and circuits. We discuss nanoscale engineered optical nonlinearities for modulation and wave mixing of optical fields, and metal-dielectric-semiconductor nanostructures and compositions to construct nanoemitters for...
In this paper, we report the feasibility of handheld systems that can both sample gas for further laboratory analysis as well as provide first field analysis by gas chromatography. In particular the systems include micro silicon preconcentrator chips that enable concentration of Volatile Organic Compounds (VOCs) by a factor of 1000 for sampling durations smaller than 1 minute, as well as micro silicon...
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