Fabrication

About: Fabrication is a research topic. Over the lifetime, 20475 publications have been published within this topic receiving 235676 citations.

A miniature flow sensor fabricated by micro-stereolithography employing a magnetite/acrylic nanocomposite resin

Abstract: Micro-stereolithography (MSL) is an important technique for fabrication of three-dimensional (3D) structures and micro-devices. With the recent developments to the MSL process such as the use of multiple resins in single components, the number of applications for devices produced with this process has expanded greatly. MSL technology is also opening up new paradigms in the area of microelectromechanical systems (MEMS) research and applications, with fabrication of custom, precise and low-cost devices a reality. MSL resins that provide functionality beyond the purely structural are required to meet the ever increasing demand for more complex sensors and devices that can be used in custom applications. Functionality can be introduced into MSL polymer resins through addition of particulate fillers into the resin matrix. Here, magnetite (Fe3O4) nanoparticles (approx 50 nm diameter) were introduced into a resin matrix and used for the fabrication of a flow sensor device. The rotation of the impeller can be determined using an external magnetic field sensor not in contact with the device. The speed of the impeller is examined to find the range over which a proportional increase in the speed with applied pressure is achieved. Such sensors could prove useful due to their rapid, low cost and custom fabrication, where the structure of the sensor can be altered/refined as required while the electronic components are retained for further use.

Microfabrication of Piezoelectric MEMS

Abstract: In this paper we present an overview of processes for fabrication of piezoelectric thin film devices using PZT (Pb(Zr x Ti1 − x )O3) in planar structures. These structures are used in cantilever-like and membrane configurations for sensing and actuation. Elaboration of a compatible wet and dry etching sequence for patterning of PZT, electrodes, SiO2 and silicon substrate is the key issues. The method for compensation of mechanical stresses to obtain flat, multilayer structures is demonstrated. Definition of membrane thickness and release of the structures are obtained by Deep Reactive Ion Etching of silicon (SOI—silicon on insulator substrates) or by surface micromachining. The complete process has been used for fabrication of cantilever arrays, ultrasonic transducers and pressure sensors. Excellent permittivity and transverse piezoelectric coefficient of PZT have been obtained with the final devices. Other examples of applications like: ferroelectric memories, nanopatterning and local growth of PZT are presented as well. The microfabrication of piezoelectric MEMS was found to be a complex task where all aspects from device design, material properties and microfabrication to assessment of performance are closely interconnected.

Fabrication and characterization of vertically stacked Gate-All-Around Si Nanowire FET arrays

Abstract: We describe the fabrication of vertically stacked Silicon Nanowire Field Effect Transistors (SiNW FETs) in Gate-All Around (GAA) configuration. Stacks with the number of channels ranging from 1 to 12 have been successfully produced by means of a micrometer scale lithography and conventional fabrication techniques. It is shown that demonstrator Schottky Barrier (SB) devices fabricated with Cr/NiCr contacts present good subthreshold slope (70mV/dec), I ON /I OFF ratio ≥ 104 and reproducible ambipolar behavior.