• Simulation Standard Technical Journal

Simulation Standard

Technical Journal

A Journal for Process and Device Engineers

Compact Multi-Level Digital-to-Analog Conversion Using Thin-Film Multimodal Transistors

Unlike conventional ohmic contact thin-film transistors (TFTs), contact-controlled TFTs [1], [2] rely on source energy barriers to produce a range of benefits including: low saturation voltages; extremely high intrinsic gain; power-efficiency; electrical stability; and uniformity of operation, notably with imprecise processes [3]. Generally, these benefits come at the expense of transconductance, however in materials such as polysilicon, similar levels of on-current can be obtained in a more compact footprint without any trace of kink-effect [4], [5].

Investigation and Explanation of PiPiN Avalanche Photo-Diode Characteristics

In this article, the operation of avalanche photo-diodes in the medium gain, continuous operation mode is investigated. In other words, we are not considering diode operation in transient “Gieger” or “single photon” detection mode, but rather in a region safely below secondary breakdown, where a well-designed avalanche photo diode can exhibit a moderate photo-generated current multiplication factor of an order of magnitude or higher.

How do I create complex shapes with fixed cross sections in Victory Mesh?

Victory Mesh versions 1.7.2.C and later include two new commands that can be used for complex shape genera-tion. The path and follow commands can be used together to generate surface meshes of general shapes based on fixed cross sections.PathThe path command connects a sequence of vertices via edges. The command operates in line or Bezier modes. In the line mode the from/to parameters are used to define the start and end of an n-dimensional line segment, for example:

Parabolic Grading of a PHEMT Channel Composition for Ultra-High and Broad OIP3 Peak

We detect a local maximum in the design space of a pseudomorphic-channel high electron mobility transistor (PHEMT). The design has an OIP3  linearity figure-of-merit that is 10-15 dBm above the baseline for a similar 1 mm width control device, and is achieved at a gate bias on the order of 100 mA/mm or less, where the ratio of transconductance to the bias current gm1/ID is particularly large (7 volt-1).

TCAD Investigation of Total Ionizing Dose (TID) Effects on Gallium Nitride HEMTs

Gallium Nitride (GaN) based devices such as the High Electron Mobility Transistors (HEMTs) find wide applications in RF and Power domain due to its excellent intrinsic properties. Accordingly, such devices have also been explored for their radiation hardness which is inherent due to the strong bonding nature of the binary and ternary nitrides. Radiation-induced instabilities including the radiation-induced stress and changes to the material properties leading to the departure of expected results in practical applications. Due to the limited availability of the test structures and facilities required to analyze the reliability of said devices under ionizing radiations, the cost and time of production gets affected. In this regard, to cut down on the cost and time for production, device engineers require accurate and reliable tools that can accurately predict the robustness of their proposed device architectures in foreign environments. Silvaco’s Victory TCAD software is one such tool that can aid the device engineers in this aspect. In this work, we demonstrate the Total Ionizing Dose (TID) Effects on GaN HEMTs using the Radiation Effects Module (REM) available with Silvaco’s Victory TCAD suite.

Obtaining Spectral Sweeps from 3D Plasmonic Structures

In the simulation standard article, “Plasmonic Light Trapping Transforming Thin-Film Photovoltaics” from 2015, the finite difference time domain (FDTD) algorithm was used in 2D to propagate the light in thin film photovoltaic structures with and without metallic nanoparticles to simulate its plasmonic effect. The solid modeling module of Victory Mesh offers the capability to model such structures in 3D.