Electronic Devices and Semiconductor Manufacturing Commons^™

Piezo-Electrochemical Transducer Effect (Pect) Intercalated Graphite Micro-Electromechanical Actuators, Glen A. Kading

Theses and Dissertations

The purpose of this research is to investigate the Piezo-Electrochemical Transducer (PECT) effect in intercalated graphite as a possible mechanism of actuation for micro-electromechanical systems (MEMS). This dissertation presents the results of research into the PECT effect in H2SO4-intercalated graphitized carbon fibers, including both electrical and mechanical characteristics of this effect. PECT fibers achieve up to 1.7% strain at 1.4 V of applied potential. In contrast, the piezoelectric material polyvinylidene difluoride (PVDF) generates only 0.01% strain and polysilicon thermal expansion between 0.02 and 0.06% strain depending on the thermal conductivity of the particular polysilicon that the actuators are fabricated in. …

Hybrid Micro-Electro-Mechanical Tunable Filter, Edward M. Ochoa

Theses and Dissertations

While advantages such as good thermal stability and processing-chemical compatibilities exist for common monolithic-integrated micro-electro-mechanically tunable filters (MEM-TF) and MEM-tunable vertical cavity surface emitting lasers (MT-VCSEL), they often require full processing to determine device characteristics. Alternatively, the MEM actuators and the optical parts may be fabricated separately, then subsequently bonded. This "hybrid approach" potentially increases design flexibility. Since hybrid techniques allow integration of heterogeneous material systems, "best of breed" compound optoelectronic devices may be customized to enable materials groups to be optimized for tasks they are best suited. Thus, as a first step toward a hybrid (Al_xGa_{1- …}

Radio Frequency Mems Switch Contact Metal Selection, Ronald A. Coutu Jr., Paul E. Kladitis, Robert L. Crane, Kevin D. Leedy

AFIT Patents

A method for selecting metal alloys as the electric contact materials for microelectromechanical systems (MEMS) metal contact switches. This method includes a review of alloy experience, consideration of equilibrium binary alloy phase diagrams, obtaining thin film material properties and, based on a suitable model, predicting contact electrical resistance performance. After determination of a candidate alloy material, MEMS switches are conceptualized, fabricated and tested to validate the alloy selection methodology. Minimum average contact resistance values of 1.17 and 1.87 ohms are achieved for micro-switches with gold (Au) and gold-platinum (Au-(6.3 at %)Pt) alloy contacts. In addition, `hot-switched` life cycle test results …

Band Gap Engineering Of Two Dimensional Silicon Photonic Crystals By Oxidation And Oxide Etching, Makhin Thitsa

Electrical & Computer Engineering Theses & Dissertations

In this thesis a thorough analysis is presented on the effects of oxidation and oxide etching on the band structure of two dimensional silicon photonic crystals (2 D Si PC's). By using the plane wave expansion method (PWM), two structures of triangular lattice, namely, air cylinders embedded in a silicon background and silicon cylinders embedded in an air background are modeled. The thesis focuses on triangular lattice arrangement because for certain parameter values such a lattice can give rise to absolute band gap, which prohibits the propagation of either transverse electric (TE) or transverse magnetic (TM) polarizations.

During oxidation three …

Investigation Of Gate Current In Neutron Irradiated AlXGa1-XN/Gan Heterogeneous Field Effect Transistors Using Voltage And Temperature Dependence, Thomas E. Gray

Theses and Dissertations

The gate current of Al₂₇Ga₇₃N/GaN heterogeneous field effect transistors (HFETs) is investigated using current-voltage (IV) and current-temperature (IT) measurement demonstrating that trap assisted tunneling (TAT) is the primary current mechanism. A thermionic trap assisted tunneling (TTT) model is used with variables of Schottky barrier height, trap energy, donor density and trap density. This results in a sigma of 1.38x10^-8 A for IT data measured between 85K and 290K and for IV data measured between 0.0 V and -4.0 V. High energy (>0.5 MeV) neutron irradiation confirms an increase of gate current with fluence. An …

The Smart Helmet, Michael Walsh

Theses

This thesis addresses the design, development and testing of a wireless sensor network for a sports helmet. The objective is to monitor an athlete's physiology and also physical impacts using a sensor network. A detailed literature review is presented addressing currently available appropriate wireless technologies, sensors and their operation, packaging, interconnections and applications. It gives a brief introduction to each sensor used in the smart helmet, accelerometers, temperature sensors, heart rate and blood oxygen sensors, along with a review of possible sensors which could be added at a later stage. The specific sensors and other related components for the helmets …

Some Aspects Of Process Control In Semiconductor Manufacturing, Keelin Relihan, Shane Geraghty, Aidan O'Dwyer

Conference papers

This paper outlines some aspects of process control in semiconductor manufacturing. Starting with an outline of the semiconductor manufacturing process, the contribution will discuss temperature control of the chemical vapour deposition stage and the control of the wafer etching process, based on the industrial experience of the first two authors. Subsequently, the authors draw the attention of the semiconductor manufacturing community to the potential of properly tuned PID controllers for the achievement of simple and high performance control solutions.