Entries by Ingrid Schwarz

Actuation Voltage For a Cantilever Switch in MEMS

Following the successful 3D simulation of the process flow of cantilever based MEMS switches using VICTORY Process is presented in August 2005 Simulation Standard article “Process Flow Simulation and Manufacture”, a novel analytical method to predict the actuation voltage for such switches is presented here. This will help extend the utility of the process simulation to the prediction of the required voltage needed for cantilever switches and the circuit design required to drive such switches.

Current Collapse Phenomenon in GaN HFETs resulting from Intentional Bulk Iron (Fe) Doping and Un-intentional Interface Traps

The Gallium Nitride-based material family has fundamental material properties which make it an attractive candidate for semiconductor device fabrication.

These properties include:

High saturation velocities and breakdown field strength
Direct bandgap, allowing fabrication of light emitting devices
The ability to form hetero-structures using aluminum or indium
Large bandgaps allowing high temperature operation

Leakage Current Calibration Procedures of Amorphous Silicon Thin-Film Transistors

Amorphous silicon Thin-Film Transistors (a-Si TFTs) are widely used as the switching device of liquid crystal display (LCD) technology. For development and analysis of a-Si TFTs, many research groups are trying to understand the physical mechanisms of a-Si TFTs. In particular, leakage current behavior is a major consideration for switching devices like a-Si TFTs. To analyze the leakage current mechanisms, calibration with numerical simulation is required.

3D TFT Simulation

Both flexible and touch panel displays have become popular for portable applications. To meet various functional requirements, system-on-panel (SOP) design has become essential [1] and different layouts as well as material have been used in the last few years [2]. Although various design and physical effects [3-5] have been successfully analyzed using 2D Technology-Computer-Aided-Design (TCAD) software, it becomes important to start to analyze and predict device performance dependent on layout effect with 3D TCAD.

The Studies of Anti-Reflective (AR) Coatings Effects for Solar Cell by Using Silvaco TCAD Tools

In 1975, screen printing was first applied to solar cells for the formation of the front and rear contacts replacing expensive vacuum metallization [1]. The encapsulate used in a photovoltaic (PV) module has many requirements. It must be optically transparent, electrically insulating, mechanically compliant, adherent to both glass and cells, and sufficiently robust to withstand 20–30 years in the field. Since the early 1980s, the encapsulate in all PV modules has been ethylene vinyl acetate (EVA) [2, 3].

Geiger Mode Simulation of Avalanche Photodiodes in ATLAS

Single-photon counting detectors are used in a wide range of applications, including astronomy, optical communications, biological sensors, and military uses. Photomultiplier tubes (PMTs) have fulfilled these needs in the past. Now, avalanche photodiodes (APDs) operating in Geiger mode as single-photon counters offer advantages over PMTs which include higher quantum efficiency, smaller size, and lower breakdown voltages. Geiger mode APDs have demonstrated single-photon sensitivites from the far infrared to the deep ultraviolet wavelengths.

ZnO based LED: A Performance Optimization through TCAD Simulation

In this paper, a two dimensional (2-D) generic model of quantum well light emitting diode (LED) based on ZnO, II-VI compound semiconductors has been reported. The structure has been designed and analyzed using ATLAS in conjuction with the BLAZE and LED modules of SILVACO software. A closed model has been developed for electrical and optical characterization of the device. The model includes all the relevant material physics and solutions of non-linear decoupled semiconductor transport and Poisson’s equations. All the radiative and non radiative recombination mechanisms have been given their due consideration in this analysis. The results obtained on the basis of numerical simulation exhibits the potential advantages of wide band gap ZnO material based LEDs over its competitive GaN material based LEDs.