Transient Simulations — Lesson 2

Simulation Settings

You can set the properties of the sources, solver, and the boundaries to vary in time to obtain the temporal response of your device. In this video lesson, you will learn about the key settings for transient simulations.

Example Device

As was mentioned earlier in the course, the CHARGE solver can simulate the time-dependent characteristics of semiconductor devices using the transient analysis. In the transient analysis, typically a time-varying voltage or optical generation source is applied to the device and its response to this time-dependent input is reported.

In this example, we will focus on the transient simulation of a germanium-based pin photodiode which was also used in the small-signal analysis unit. The geometry of the photodiode is simplified to be a single germanium slab sandwiched between two metal contacts as shown in the diagram below. The top and bottom surfaces of the germanium slab are doped with p- and n-type dopants respectively. The rest of the slab is left undoped creating a pin device. We will perform transient analysis on the pin diode to extract its large-signal transient step response to illumination which is then used to obtain its frequency-dependent bandwidth.

Demo

The simulation project and script file used in this unit can be downloaded here.