Characterization of an Acetone Detector based on a Suspended WO3-Gate AlGaN/GaN HEMT Integrated with Micro-heater

A suspended AlGaN/GaN high electron mobility transistor (HEMT) sensor with a tungsten trioxide (WO 3 ) nanofilm modified gate was microfabricated and characterized for ppm-level acetone gas detection. The sensor featured a suspended circular membrane structure and an integrated microheater to select the optimum working temperature. High working...

Hydrogen sulfide detection properties of Pt-gated AlGaN/GaN HEMT-sensor

AlGaN/GaN high electron mobility transistor (HEMT)-based sensors with catalytic platinum gate were micro-fabricated on commercially available epitaxial wafers and extensively characterized for ppm level hydrogen sulfide (H₂S) detection for industrial safety applications. High operating temperature above 150 °C enabled large signal...

System in package (SiP) technology: Fundamentals, design and applications

Purpose: The purpose of this paper is to demonstrate a novel 3D system-in-package (SiP) approach. This new packaging approach is based on stacked silicon submount technology. As demonstrators, a smart lighting module and a sensor systems were successfully developed by using the fabrication and assembly process described in this paper. Design...

Pt-AlGaN/GaN HEMT-sensor layout optimization for enhancement of hydrogen detection

This paper reports on the layout optimization of Pt-AlGaN/GaN HEMT-sensors for enhancing hydrogen sensor performance. Sensors with gate width and length ratios W_g/L_g from 0.25 to 10 were designed, fabricated and tested for the detection of hydrogen gas at 200 °C. Sensitivity, sensing current variation and transient...

Thermal characterization of carbon nanotube foam using MEMS microhotplates and thermographic analysis

Thermal material properties play a fundamental role in the thermal management of microelectronic systems. The porous nature of carbon nanotube (CNT) arrays results in a very high surface area to volume ratio, which makes the material attractive for surface driven heat transfer mechanisms. Here, we report on the heat transfer performance of...

Precision Recess of AlGaN/GaN with Controllable Etching Rate Using ICP-RIE Oxidation and Wet Etching

A method for highly controllable etching of AlGaN/GaN for the fabrication of high sensitivity HEMT based sensors is developed. The process consists of cyclic oxidation of nitride with O₂ plasma using ICP-RIE etcher followed by wet etching of the oxidized layer. Previously reported cyclic oxidation-based GaN etching obtained very...

Particle Imaging and Flow Visualization of In-situ TEM Nanoreactors

Mechanical Robustness and Hermeticity Monitoring for MEMS Thin Film Encapsulation

Many Micro-Electro-Mechanical-Systems (MEMS) require encapsulation, to prevent delicate sensor structures being exposed to external perturbations such as dust, humidity, touching, and gas pressure. An upcoming and cost-effective way of encapsulation is zero-level packaging or thin-film encapsulation. With this method, MEMS are already sealed...

Electro-thermal analysis of MEMS microhotplates for the optimization of temperature uniformity

This paper presents a microhotplate working up to 1200 °C with improved temperature uniformity by optimizing the geometry of the thin-film resistor. By varying the linewidth of meandering resistive tracks, heat is generated in such a way to have more homogenous temperature distribution. The microhotplates are fabricated using molybdenum as...

Method of manufacturing a micro unit and a micro unit for use in a microscope

The invention relates to a method of manufacturing a micro unit for use in a microscope. The method comprises the step of providing a planar substrate supporting structure and creating a chamber in the supporting structure for receiving a fluid containing a chemically reacting substance to be inspected. Further, the method comprises the step of...

Wafer-level assembly and sealing of a MEMS nanoreactor for in situ microscopy

This paper presents a new process for the fabrication of MEMS-based nanoreactors for in situ atomic-scale imaging of nanoparticles under relevant industrial conditions. The fabrication of the device is completed fully at wafer level in an ISO 5 clean room and it is based on silicon fusion bonding and thin film encapsulation for sealed lateral...