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We present an extension of the method for thermal characterisation named “Raman Thermometry” that relaxes the assumption of boundary conditions by spatially resolving the thermal field. The technique is contact-less and suitable to study nanoscale systems unattainable to other by other more invasive thermal characterisation techniques.
Heat generation in integrated circuits has become in few decades one of the most limiting factors for performance improvement in mobile device components, such as cell phones or tablets. In these devices, heat dissipation is limited to a few Watts as state of art cooling systems, such as heat-sinks or fans, do not fit with the dimensional and power consumption constraints. Amongst the solutions proposed...
In this paper, a novel parametric moment matching technique is proposed for efficiently constructing accurate parametric compact thermal models for variable geometries. This result is achieved by reformulating the heat diffusion equation in a parametric-dependent domain as a heat diffusion equation in a reference domain wherein the geometry is fixed and material parameters are variable. The approach...
By the use of novel techniques like Silicon-on-insulator (SOI) wafer and electron beam lithography (EBL), the development of new types of NEMS-sensors, like a nanoscale Thermal-Time-of-Flight (TToF) sensor, are possible. While scaling the dimensions to a nanoscale level, new side effects will become non neglectable. Within the research and development of a nanoscale TToF sensor such a side effect...
Solid propellants are used in various flight and underwater systems as well as in propulsion platforms. Micromachining, microelectromechanical systems (MEMS) and automatic dispensing of high-energy-density nanoenergetic materials are examined for current and next generation of application-specific flight and underwater platforms. The integrated MEMS-technology microthrusters with the optimized-by-design...
We present the design for a MIR integrated source based on the thermal emission of a heated silicon waveguide. With a temperature of 1000 K a total power of 0.47 μW can be achieved.
We fabricated wavelength tunable laser diodes with Si photonic wire waveguide ring resonators as an external optical cavity. The continuous wavelength tuning operation was demonstrated using by the micro heaters. Our wavelength tunable laser diode is suitable for digital coherent optical transmission systems based on wavelength division multiplexing.
Different micro-heaters structures are analyzed and experimentally demonstrated to optimize the thermo-optic tuning performance of silicon MMIs. A 28dB crosstalk with 65 mW power consumption has been achieved for a double meander structure.
In this paper, a numerical simulation of thermal transport at the nanoscale is developed by solving the phonon Boltzmann transport equation by the Monte Carlo method. A full phonon dispersion is used to determine accurately the vibrational frequencies and group velocities of all phonon modes. Simultaneous conservation of energy and momentum in anharmonic phonon-phonon scattering events in enabled...
The photo-thermal properties of vertically etched gallium arsenide nanowire arrays are examined using Raman spectroscopy. The nanowires are arranged in square lattices with a constant pitch of 400 nm, and diameters ranging from 50 to 155 nm. The arrays were illuminated using a 532 nm laser with an incident energy density of 10 W/mm2. Nanowire temperatures were highly dependent on the nanowire diameter,...
Nano scale actuators consisting of a free-standing bilayer of ferromagnetic shape memory alloy (FSMA) and silicon with critical lateral dimensions of 250 nm are designed, nanofabricated and characterized in-situ in a scanning electron microscope (SEM). Upon Joule heating and cooling, fully reversible nano actuation in out-of-plane direction of up to 4 % of actuator length is observed. In-situ measurements...
In utilizing CMOS-MEMS resonators as mass-sensitive platforms, a uniform temperature distribution on the membrane surface is critical. In this paper, a novel design of CMOS-MEMS resonator with embedded microheater to control the temperature over the sensing layer was successfully designed and characterized. The CMOS-MEMS resonator was fabricated using 0.35 µm CMOS and post-CMOS micromachining process...
The on-going effort of integrating heterogeneous circuits as well as the increasing length of global interconnect are driving the semiconductor community towards 3-D integrated circuits. In this work, thermal paths within a 3-D stack are investigated using the HotSpot simulator, and the results are compared to experimental data of a fabricated two layer stack with a single back metal layer. Resistive...
We show that with a Full-Band dispersion, the specific heat is closer to the experimental value than with an isotropic quadratic dispersion. So we use a Full-Band dispersion in the transport algorithm. A Monte Carlo algorithm has been developed to simulate phonon transport in silicon nanowire. It has been successfully used to simulate the thermal conductivity.
This paper presents the design of complementary metal-oxide-semiconductor (CMOS) based thermal energy generator (TEG). Energy harvesting techniques have been employed as to extend the lifespan of various battery-operated applications for many years. Among numerous techniques available, thermal energy harvesting has proven to be a widespread practice in harvesting electrical energy as heat can be found...
We present a quantum approach to simulate self-heating effects in transistors based on silicon nanowires and estimate the resulting performance degradation. Our self-consistent thermoelectric simulations are based on the nonequilibrium Green's function approach and provide the heat power transferred from electrons to phonons, thus allowing the calculation of the local temperature and its impact on...
The excellent characteristics (low power loss, high speed/high temperature operation) of SiC semiconductors can contribute to realizing smaller power converter with a higher power output. Using our own packaging technology of double-sided cooling and SiC devices, we have developed the new, small 6-in-1 power module with high output power density. If the inductance of the main circuit is large, it...
A double-pulse technique for the I/V characterization of GaN-based transistors is adopted for the nonlinear modeling of a 0.25 µm AlGaN/GaN on SiC FET. Experimental validation is provided by means of large-signal PA performance prediction both at low-frequency, in order to outline the role played by the resistive drain current source, and at microwaves. Improved prediction accuracy is demonstrated...
Thermal conductivity λ of gases was successfully measured by a simple steady state method using a microbridge type MEMS sensor fabricated on a Si substrate. The sensor consisted of a hot wire with two adjacent thermocouples on the surface of a SiO2 microbridge. The temperature increase of the microbridge was measured by supplying step-like electrical power Q to the hot wire. Due to the small heat...
In this work, a thermally stable air-bridged matrix (ABM) AlGaN/GaN high electron mobility transistor (HEMT) with micromachined diamondlke carbon (DLC)/Titanium thermal-distributed layers was demonstrated. After removing the Si substrate beneath the HEMT, the DLC/Ti heat dissipation layers were deposited on the backside of the HEMT, and a significant breakdown voltage improvement was observed. The...
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