• Simulation Standard Technical Journal

Simulation Standard Technical Journal

A Journal for Process and Device Engineers

Hints, Tips and Solutions – How to best visualize vectors and field lines in TonyPlot

Traditionally, visualizing vectors by means of arrows in TonyPlot was a challenge, especially in the areas where the computational grid was dense. The vector arrows were plotted for every grid point, making them in many cases very hard to discern. One such example is illustrated in Figure 1.

Hints, Tips and Solutions – Scattering mechanisms contributing to reduced channel mobility in 4H-SiC MOSFETs

In a MOSFET structure, silicon carbide, 4H-SiC in particular, is known to exhibit lower channel mobility than Si, mainly due to Coulomb scattering at trapped charge at the SiO2/4H-SiC interface, where a high interface trap density exists. Atlas provides an alternative inversion layer mobility model specifically intended for 4H-SiC. The model enabled by specifying the ALTCVT.N parameter for electrons or the ALTCVT.P parameter for holes on the MOBILITY statement takes into account four scattering mechanisms. These comprise the ionized impurity scattering in the bulk semiconductor, the surface roughness scattering, the acoustic surface phonon scattering, and the Coulomb scattering at trapped charge at the SiO2/4H-SiC interface. Using Matthiessen’s rule, the ALTCVT.N and ALTCVT.P model combines four mobility components related to their respective carrier scattering to form the total inversion layer mobility in 4H-SiC.

Soft Error

A soft error in the context of this article, can be defined as an unintended change in electrical state of a device or circuit, that has an origin, external to the system’s designed inputs and outputs. A “soft” error is one which causes no direct permanent damage to the systems components, such that the unintended system behavior can be corrected with some form of “re-set”.

Hints, Tips and Solutions – Types of 3D Delaunay Shape Refinement

Q: What Types of 3D Delaunay Shape Refinement can be used in Victory Process?A. The Victory Process cell mode Delaunay 3D device meshing algorithm already includes various TCAD-based local refinement algorithms to ensure accurate and robust device simulation. These include junction and interface distance refinement. One benefit of these approaches is that complex refinement behavior can be specified via a simple deck interface, but a limitation is that the results can only vary according to the small number of parameters of the schemes. In some cases, such as particle path refinement, it can be useful to have finer, more local control over the mesh and the shape distance refinement schemes have been produced to support this.

Blue LED Simulation

It is very important to understand the operation and underlying physics of InGaN/GaN materials based electronic device in modern display industry such as flat-panel-display for back-light illumination and high efficiency light bulbs. For these reasons, the numerical device simulation is adapted to study the improvement of LED efficiency and to understand the basic operation of multiple quantum well LEDs.

Unified Victory Conformal Export for 2D Process Mode

Victory Process can operate in either 1, 2 or 3-dimensions and can produce one of two different geometric representations: cell mode and process mode. Cell mode structures are generally composed of large, flat geometric parts but process mode structures may be smoothly varying and only very locally flat. Device meshes of cell mode structures resolve the input shape precisely but this is undesirable for the case of process mode structures as it would result in very finely sampled meshes which would be unsuitable for device simulation.