This article focusses on the use of Silvaco International’s schematic capture and editing tool Scholar combined with Verilog A. Verilog A is a standard language used for behavioral level modeling. Verilog A combined with Scholar forms a powerful tool capable of running both schematics with Verilog A modules and mixed Verilog A and physical model simulations. Verilog A may also be used in an environment for compact model development but primarily it is used to reduce schematics of significant amounts of transistors into efficient maintainable and changeable blocks which can be instantiated on any level of a design.

The transient simulation uses an adaptive time-stepping algorithm depending on the change in the circuit waveforms (dV/dT). This means the simulated waveform consists of uneven time steps (more time points are required round a rapidly changing voltage to define the detail). If the normal .FFT command is used, these varying time points need to be interpolated to a regular set to allow the FFT plot to be created.

Silvaco’s Expert tool is an extremely powerful layout-editing tool that supports features related to parameterized cells. Parameterized cells, often called P-cells, increase designer productivity by adding enormous flexibility and efficiency to the design process. While standard cells help the designer to avoid repetitive drawing of identical pieces of layout, P-cells extend this functionality to the specific parameters that define the mask geometry. As a result, P-cells assist in the automation of layout design and help speed-up modification through the revision of P-cell parameters instead of wasting valuable resources by repeatedly redrawing the layout geometry.

We have lots of cells that become off-grid when we do cut-and-paste from other cells. We tried to use the “Tools->Snap Selected to Grid” command, but the cell doesn’t get moved at all. How does Snap to grid works for Instances? Does it work for Instances?

In order to investigate the influence of ridge separation on the transverse optical modes of a double ridge edge multiple quantum well (MQW) emitting laser, we have designed a generic device based on the InGaAsP/InP MQW 1.5µm wavelength emission. The aim of this study is to investigate power loading in the structure with increasing bias using the bottom layer as the reference plane.