• TCAD Examples

    TCAD Examples

mos2ex28.in : Growing SiGe Source-Drain Stressors using Direction Dependent Epitaxy

Requires: Victory Process 3D Diffusion & Implantation, 3D Physical Etch & Deposit, Victory Stress 3D, Victory Mesh 3D, Victory Device 3D
Minimum Versions: Victory Process 7.58.2.R, Victory Mesh 1.8.2.R, Victory Device 1.18.0.R

This example creates a FinFET similar to example mos2ex26, but instead of using geometric etch-deposit commands in Victory Process Cell Mode operation, it uses realistic crystal direction dependent epitaxy in Process Mode to create the SiGe source-drain extention stressors.

To invoke Process Mode operation, the "resolution" parameter is defined in the "init" statement. Most importantly, for subsequent stress simulation, the statement: "method stress.latticemismatch=true" must occur in the input file before any deposited materials that need to be taken into account in the stress calculations. The most suitable location for this statement, is therefore at the begining of the input file, just after any "line" statements.

The properties of the crystal dependent epitaxy process are first defined using the "EtchDepoProperties" statement, for each of the materials exposed during the epitaxy process and for each crystal direction for the crystalline materials. Here we are effectively defining the properties of one particular epitaxy machine, of which there may be several, so in order to specify which machine we are using later in the process, we assign this particular machine a name. In this case, the epitaxy machine is called "sige_sd". This machine name must then be specified in any subsequent epitaxial deposit statement in which we wish to use this machine with these particular properties.

It is important to note that all we have done with the "EtchDepoProperties" statement is define the properties of our epitaxy machine. We have not simulated any epitaxy process yet. The actual crystal dependent epitaxy process step is invoked using the following "Deposit" statement. This statement is fairly self explanatory, and simply specifies how long we wish to run the epitaxy machine, together with any in-situ doping and material X-composition.

After the epitaxy, the new stress incorporated into the structure is calculated on the following "Stress" statement. The resultant strain in the channel resulting from the stress induced from the SiGe source-drain epitaxy extensions, enhances hole mobility as evidenced by an increase in unsaturated drain current. The strain enhancement model is invoked in Victory Device on the "mobility" statement, using the parameters "nhance" and "phance".

The first device simulation calculates the un-saturate IdVg curve without invoking the strain enhancement calculations, whilst the second device simulation takes strain into account. The difference due to the strain enhanced hole mobility is shown in the final plot.

To load and run this example, select the Load button in DeckBuild > Examples. This will copy the input file and any support files to your current working directory. Select the Run button in DeckBuild to execute the example.

Input Files
Output Results
These examples are for reference only. Every software package contains a full set of examples suitable for that version and are installed with the software. If you see examples here that are not in your installation you should consider updating to a later version of the software.
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