2.3 Simulator Control

Additionally to the definition of the geometry, the grid information, and the quantities associated with a grid or a geometry, a simulator needs some more information which includes

• The definition of the data flow (i.e. the names and file formats of the persistent input and output Wafers).

• The definition of the models to apply and the quantities to treat in the simulation respectively.

• The definition of simulator internal parameters like, e.g., the time integration parameters for transient problems, or the iteration scheme that is to be used in the equation solver.

• A material database.

• Some simulations require the definition of circuitry information.

This additional information is either stored in an extra file, the so-called input deck, or passed on the command line of the simulator if applicable (depending on the number of parameters). Sometimes a combination of command line options and input deck is useful (e.g. to supply input and output file names on the command line, but use an input deck for model parameters).

An input deck database (IPD) that is capable of holding an arbitrary number of (simulator specific) parameters was developed at the Institute for Microelectronics [24,25]. The database provides a static object-oriented description language. It allows to group parameters into sections and inherit from one section into another. This inheritance mechanism is particularly useful in conjunction with a large number of parameters and to define hierarchical information. In this case default values for all parameters are supplied with the simulator in a defaults section. This section is inherited into a user definable section where only those parameters that need to be changed are listed.

This input deck database is also used to define circuitry information necessary to run mixed mode device simulations with the device simulator MMNT [26,27]. In the case of a mixed mode simulation several input Wafers are used. Connections between the Wafers (i.e. the circuitry information) are established by identifying the contacts of the devices. Fig. 2.4 depicts the data flow for the case of a mixed mode device simulation.

Figure 2.4: Data flow for a mixed mode device simulation. The geometry and dopant concentrations from two devices (Wafer 1 and Wafer 2) are taken as input to the device simulator. The names of the devices and contacts that are connected are stored in a separate file, the input deck. This file also contains simulator specific options like the models to use in the simulation or if and which quantities have to be stored on the optional output Wafers.

2003-03-27