3.4.1 Quantity Module

Depending on the application area several different quantity types can be distinguished:

• Mixed-mode quantities describe a physical quantity for each node of the simulation circuit. Examples are the node voltage or the node temperature.
• Global device quantities are used within a certain device and describe a quantity for all segments of this device. Examples are the device temperature in case of isothermal simulation or the total heat energy.
• Segment quantities are defined on certain segments of a device. Whether they exist or not depends on the segment material and on the models taken into account for the current simulation. The impurity concentration, for example, can only be defined on semiconductors and insulators, the Auger generation/recombination rate can only be defined when, e.g., electrons and holes exist for that segment and the Auger-model has been activated.
• Boundary quantities are defined only for boundaries between two segments. An example is the displacement of the electric field.

The quantity module supports all these types of quantities and manages data storage, instantiates, modifies, or deletes quantities on demand and controls access to the information stored in these objects. Thereby it manages several existing quantity types (see Fig. 3.4) which are explained in the next section.