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Generates the actual device described in the Epi tool by specifying the device grid and mesh refinements.
Application of contacts to the device, construction of the grid and doping data, and generates mesh refinements.
sense_ug.pdf [2]
MatPar Builds the material parameter files used in the Sentaurus Device simulation.
All of the important material parameters are generated based on temperature and specific material requirements. See ../pardb/index.html for more information.
epi_matpar_ug.pdf [1]
Sentaurus Device
Device simulator. Uses the outputs of previous tools to run the actual simulation (see Figure 9).
sdevice_ug.pdf [3]
Inspect Curve display program. Simulation output can be plotted using Inspect, such as current–voltage characteristics.
Documentation on Inspect.pdf [4]
Tecplot Specialized plotting software.
Dedicated for scientific visualization of the simulation results, for example, energy band diagrams and cross-sectional 2D or 3D data.
Tecplot User Guide.pdf [5]
Accessing a tool‟s command file is important in modifying simulation parameters and adding
variables to the Sentaurus Workbench.
An important aspect of understanding how Sentaurus works is understanding how the tools
communicate with each other, which is referred to as the tool flow, shown in Figure 9.
Application Note: Understanding Synopsys Sentaurus Page 12 of 14
Figure 9: Simulation Tool Flow in Sentaurus Workbench
Epi tool
Purpose: Easily creates a multilayered epitaxial stack.
Input: command_epi.csv comma separated values (csv) command file which specifies
the material, thickness, doping concentration, mole fraction and mesh size for
each layer.
Output: nX_epi.scm, which becomes input to the Structure Editor tool, and
nX_epi.tcl, which becomes input to the MatPar tool.
Sentaurus Structure Editor tool
Purpose: Generates the actual device described in the Epi tool by specifying the device
grid and mesh refinements.
Input: sde_dvs.cmd (command file), and
nX_epi.scm (output from the Epi tool) which is imported via the command
load @episcm@ that is located in its command file sde_dvs.cmd. The
Structure Editor adds the contacts to the structure and generates the grid,
meshing, and doping information through its output file.
Output: grid_mesh.tdr, which becomes input to the Device tool.
MatPar tool
Purpose: Builds the material parameter files used in the Sentaurus Device simulation.
Input: material.tcl is a tcl based file that allows the user to describe specific
material models (such as bandgap, mobility, etc),
material.par is a file that includes all relevant material parameters required
for Sentaurus Device; this file can be used instead of the material.tcl file,
model.tcl is a tcl based file used to model the parameter of a material as a
function of its dependencies (for example, temperature or doping); these model
command_epi.csv
Epi Sentaurus
Structure Editor MatPar Sentaurus Device
nX_epi.scm
nX_epi.tcl
sde_dvs.cmd
grid_msh.tdr
material.tcl
material.par
model.tcl MatPar_mpr.cmd
nX_mpr.par
sdevice_des.cmd
current_des.plot
plot_des.plot
Application Note: Understanding Synopsys Sentaurus Page 13 of 14
files are found in the material parameter database (../pardb/),
MatPar_mpr.cmd (command file), and
nX_epi.tcl (output from the Epi tool) which is called via the command
source @pwd@/@epitcl@ that loads all the layer variables and generates each
material parameter file to the /npar directory using the material parameter
database directory ../pardb. The command file also specifies the temperature
of the simulation through the variable @temp@ defined in the Workbench. For
more information on this process, refer to [6].
Output: nX_mpr.par, which becomes input to the Device tool as a pointer to all MatPar
generated material parameter files located in the /npar/ directory.
Sentaurus Device tool
Purpose: Specifies the electrodes of the structure, the physical models, the output plot
data, the mathematical parameters for the simulation, and finally, the equations
to simulate (for example, Poisson, electron and hole continuity equations).
Input: sdevice_dvs.cmd (command file) that imports the material parameter files
(outlined in nX_mpr.par) built by MatPar using the material.tcl in
conjunction with the model.tcl files, and
nX_msh.tdr (output from the SentaurusSE tool) that contains the grid and
meshing data.
Output: current_des.plot, which becomes input to the Inspect tool, and
plot_des.plot, which becomes input to the Tecplot tool.
Sentaurus Workbench Variables
The Sentaurus Workbench has specific variables defined for each tool. These allow you greater
flexibility in bypassing the editing of the tool‟s command file, and are useful in studying the
variation of a parameter and its effects on the simulation. For more information on the
Workbench, see [7].
To add a variable:
1. Right-click on the row below the tools.
2. Select Add.
3. Define the string of the variable along with its default value.
Note: Multiple values can be added to a specific variable by right clicking and selecting Add
Values.
This variable will have to be defined in the specific tool‟s command file as @string@. For
example, the width of the p-n junction is defined as “wtot” in the Sentaurus Workbench (see
Figure 2) and is explicitly referred to as @wtot@ in both the Epi and Sentaurus Device command
files.
Application Note: Understanding Synopsys Sentaurus Page 14 of 14
Errors and Debugging
Sentaurus maintains a log for each node‟s simulation activities. Each log file is named in the
format nX_tool.log
where X represents the node number, and tool is a three-letter abbreviation referring to the tool
of the node (for example, mpr for MatPar).
Similarly, Sentaurus generates error files named nX_tool.err that can be accessed easily
through the View Output or Node Explorer options explained on page 7 and shown in Figure 6.
Note: It is important that you know node numbers. They can be seen on the Sentaurus
Workbench by pressing F9.
Summary
Synopsys Sentaurus is a powerful software package capable of simulating the electrical, optical
and thermal properties of complex semiconductor devices. This application note outlines the
necessary steps to launch the software and run the GaAs p-n junction tutorial project developed
by the author. It then describes the tools capable of modeling and simulating the diode and how
they interact in the simulation tool flow. Lastly, errors and debugging were discussed in a way as
to direct the user to the proper error and log files for more specific information.
You are encouraged to read the Template for Creating and Simulating Multilayered
Heterostructure Devices user guide [6] for further information on the use of the Epi and the
Sentaurus Structure Editor tools.
References
[1] “Epi/MatPar User Guide,” Synopsys, Inc. (2008).
[2] “Sentaurus Structure Editor User Guide,” Synopsys, Inc. (2008).
[3] “Sentaurus Device User Guide,” Synopsys, Inc. (2008).
[4] “Inspect User Guide,” Synopsys, Inc. (2008).
[5] “Tecplot User Guide,” Synopsys, Inc. (2008).
[6] “Template for Creating and Simulating Multilayered Heterostructure Devices,” Synopsys,
Inc. (2008).
[7] “Sentaurus Workbench User Guide,” Synopsys, Inc. (2008).