Entries by Erick Castellon

Estimation of Interface Property Changes Between Normally On/Off Hydrogenated Diamond MISFETs

September 3, 2019in /by

Introduction
Diamond is considered to be the ultimate semiconductor material for high power and high frequency devices due to its superior electrical and thermal properties, such as high breakdown field, high carrier mobility, low dielectric constant, and high thermal conductivity, as shown in Table 1.

Furthermore, diamond has some unique electronic properties. The surface of diamond films terminated by hydrogen atoms has negative electron affinity (NEA) and can generate a two-dimensional hole accumulation layer suitable as a hole channel of a field-effect transistor.

TCAD Simulation of Electric Field Distribution in Gallium Nitride Trench-based Power Devices

July 5, 2019in /by

Introduction

Gallium nitride (GaN)-based devices are excellent candidates for high-voltage and high-power applications, due to the superior physical properties of GaN compared to Si, SiC, and GaAs. Recently, GaN vertical devices have attracted increased attention, due to their advantages over GaN lateral devices, including high breakdown voltage (BV) and current capability for a given chip size, and superior thermal performance.1 Recent demonstrations of high-performance vertical GaN diodes2–4 and transistors5–9 have made vertical structures very promising for GaN power devices.

Channel-length Dependence of a-IGZO TFTs with Self-heating Effects

July 4, 2019in /by

Introduction

Amorphous In-Ga-Zn-O thin-film transistors (a-IGZO TFTs) show a high mobility, a small sub-threshold swing, and a low OFF-current, and they are considered to be one of the most promising TFT for new flat-panel displays (FPDs). The high mobility originates from the unique electron transport in a-IGZO. The transport properties are different from those in conventional semiconductor materials like Si, for example, the mobility increases with increase of the electron concentration and/or temperature. Therefore, the new mobility model for a-IGZO is necessary. In addition, as pixel sizes in the FPDs decreases, a channel-length, L, of a-IGZO TFTs becomes shorter. It indicates that it is important to understand the operation of short-channel a-IGZO TFTs.

Simulation of Different Tunnel Junctions in InGaP/GaAs, InGaP/CdTe Dual Junction Solar Cells

July 3, 2019in /by

Abstract — Dual junction solar cells were simulated using Silvaco TCAD tool with various tunnel junction material compositions. InGaP/GaAs dual junction solar cells were simulated with 10 different tunnel junction combinations. The highest efficiencies were from InGaP/AlGaAs and InGaP/InGaP tunnel junctions at 31.82% and 31.75%. InGaP/CdTe solar cells were also simulated with four different tunnel junction combinations. InGaP/InGaP tunnel junction was found to be most efficient with 37.29% which is consistent with experimental data. Three of four InGaP/CdTe dual junction solar cells were simulated to have higher efficiency values than all InGaP/GaAs solar cells.

Hints, Tips and Solutions – July, August, September 2019

July 1, 2019in /by

Q. Is it possible to emulate a deep reactive ion etch process (e.g. deep trench with scalloped sidewalls) without using a physical based process simulation, such as Victory Process?

To study a non-ideal geometry and its impact on device performance, TCAD device engineers may want to generate structures with complex geometries quickly, without the added details of physically-based process simulation.

Device Simulation – New Features in 2019 Baseline Release

April 1, 2019in /by

The effect of Coulomb interaction in the absorption spectrum of quantum wells (QWs) is responsible for the quantum confined Stark effect (QCSE), which is the physical mechanism underlying the operation of electro-absorption modulators [1].
A new model has been added to Atlas to simulate QCSE in QWs and can be enabled with the following command (the qwell model must also be activated):

Interactive Tools – New Features in 2019 Baseline Release

April 1, 2019in /by

DeckBuild is Silvaco’s state of the art simulator interface. It is capable of running all simulators from Silvaco as well as many of the visualization tools. Figure 4-1 shows an overview where a simulation was successfully finished and the results can be inspected. Values that were extracted from a structure file are shown in the top right part of the window.