The Electrical/Thermal Material Database allows you to manage (create, modify, delete) the materials that are available for use in simulations. It allows for the definition of complex materials using parametrized models. This database stores the electrical and thermal properties of materials used in CHARGE and HEAT simulations. It also provides an interface to change material properties like color, and model parameters.
The material list shows the materials stored in the material database. A number of materials are provided with the product installation. To create additional materials, use the ADD button. You can also modify some of the material properties (name, color, mesh order, etc) in the list view. A copy of the database is stored in each simulation file. A change to the database in one file does not automatically change the materials in any other files.
Default Electrical/Thermal Materials
The default electrical/thermal material database of CHARGE and HEAT includes a number of common materials used in electrical and thermal simulations, including conductors, insulators, semiconductors, and fluids (air). When starting a new project, the default database will be loaded. The default materials cannot be edited directly, however changes made to the materials will be saved with the project. If you wish to modify one of the default materials, the default project file must be edited.
Accessing the material database
The electrical/thermal material database can be accessed through the Electrical and Thermal Materials button on the Design tab. In the material database, materials are listed in the table, which identifies the material name and type, as well as other properties. Below the material table, the properties for the currently selected material are displayed.
Materials in the default material database
The following materials are included in the default material database.
- GaAs (Gallium Arsenide)
- AlAs (Aluminum Arsenide)
- InAs (Indium Arsenide)
- AlP (Aluminum Phosphide)
- InP (Indium Phosphide)
- GaP (Gallium Phosphide)
- AlN (Aluminum Nitride)
- InN (Indium Nitride)
- GaN (Gallium Nitride)
- GaSb (Gallium Antimonide)
- AlSb (Aluminum Antimonide)
- InSb (Indium Antimonide)
- CdS (Cadmium Sulfide)
- CdSe (Cadmium Selenide)
- CdTe (Cadmium Telluride)
- Si (Silicon)
- Ge (Germanium)
- SiGe (Silicon Germanium)
- AlGaAs (Aluminum Gallium Arsenide)
- InGaAs (Indium Gallium Arsenide)
- InAlAs (Indium Aluminum Arsenide)
- InAsP (Indium Arsenide Phosphide)
- GaAsP (Gallium Arsenide Phosphide)
- InGaP (Indium Gallium Phosphide)
- AlGaN (Aluminum Gallium Nitride)
- InGaN (Indium Gallium Nitride)
- GaAsSb (Gallium Arsenide Antimonide)
- AlGaSb (Aluminum Gallium Antimonide)
- AlAsSb (Aluminum Arsenide Antimonide)
- InAsSb (Indium Arsenide Antimonide)
- InAlSb (Indium Aluminium Antimode)
- AlGaP (Aluminum Gallium Phosphide)
- AlInP (Aluminum Indium Phosphide)
- Al2O3 (Aluminium oxide) - Robertson
- HfO2 (Hafnium oxide) - Robertson
- Si3N4 (Silicon nitride) - Sze
- SiO2 (Glass) - Sze
- TiO2 (Titanium oxide) - Robertson
- ZrO2 (Zirconium dioxide) - Vitanov
- Ag (Silver) - CRC
- Al (Aluminium) - CRC
- Au (Gold) - CRC
- Cu (Copper) - CRC
All fluid materials are treated as insulators in the electrical (CHARGE) simulation. And the materials are defined by the permittivity.
Visualizing the semiconductor properties
The properties of semiconductor materials such as mobility, carrier lifetimes and so on can be visualized as a function of various variables by clicking the "Visualize" button in the main window of the Electrical/Thermal Material Database after selecting the desired semiconductor material from the list. The following variables and semiconductor properties are available for visualization in the semiconductor properties visualizer dialog:
- T: Temperature in the units of Kelvin (K)
- N: Doping concentration in the units of 1/cm3
- NA: Acceptor doping concentration in the units of 1/cm3
- ND: Donor doping concentration in the units of 1/cm3
- F: Field intensity in the units of V/m
- x: Alloy fraction (only available for alloy materials)
- epsr: Relative dielectric permittivity
- Eg: Band gap in the units of ev
- mn: Effective mass of electron (m*/m0)
- mp: Effective mass of hole (m*/m0)
- mun: Electron mobility in the units of cm2/V.s
- mup: Hole mobility in the units of cm2/V.s
- vsatn: Electron saturation velocity in the units of cm/s
- vsatp: Hole saturation velocity in the units of cm/s
- taun: Electron SRH life time in the units of s
- taup: Hole SRH life time in the units of s
- copt: optical capture coefficient for radiative recombination in the units of cm3/s
- caun: Auger recombination capture coefficient for electrons in the units of cm6/s
- caup: Auger recombination capture coefficient for holes in the units of cm6/s
Each semiconductor property can be plotted as function of one or two variables chosen in first and second axis drop down menu. The plot range, number of points, and the scale (linear or log) for each variable can also be selected from the this window. Any desired number of semiconductor properties can be chosen for a single plot by checking the name of each property in the window. To plot the selected properties, simply click the "Create Visualization" button. Users can also send the selected property to script workspace for further processing by clicking the "Send to Script" button. Once done, you can click the "< Done" button to go back to the property editor window.
Semiconductor properties visualizer dialog
Electron and hole mobilities for Si visualized as a function of temperature
Modifying default materials
The first column of the list shows which materials are write protected. To modify the default materials that appear when you create a new simulation, edit the simulation file in the defaults sub-directory of the installation directory. For example, you could create a new database that contains only the materials required for your simulations.
Note: Materials currently used in the simulation cannot be deleted.
If a material is being used in the current project, a "no delete" icon will indicate that the material can be modified but not erased. To delete these materials, first modify the simulation so they are not used.
Use the Material properties box on the right of the Material list to view and edit the material model parameters. For model parameter definitions, see Electrical/Thermal Material Models.