NPN - Gummel plot in 2D and 3D : NPN - Gummel plot in 2D and 3D

Requires: S-Pisces/Device 3D
Minimum Versions: Atlas 5.28.1.R

This example simulates a Gummel plot for a silicon BJT in 2D and 3D. It shows:

  • Formation of a 2D NPN BJT using Atlas syntax
  • Ic and Ib extraction versus Vbe (Gummel plot) of the 2D structure
  • Formation of a 3D NPN BJT using Atlas syntax
  • Ic and Ib extraction versus Vbe (Gummel plot) of the 3D structure

The initial stage of the example uses the mesh, region , and electrode statements in Atlas to construct the 2D NPN structure. Analytical doping profiles are added in the doping statement. The structure has a heavy n+ emitter, 1.0e18 peak base concentration, a buried collector layer and heavy p+ extrinsic base contact.

The models bipolar statement is set to specify that the default set of bipolar models is to be used. The default set of bipolar models includes: concentration dependent mobility, field dependent mobility, band-gap narrowing, concentration dependent lifetimes and Auger recombination.

The gummel plot syntax is similar to that described in the first example of this section. Following the calculation of the gummel plot for the 2D structure, go atlas triggers the initiation of an Atlas run that will be used to perform an equivalent calculation in 3D. The 3D mode of Atlas is triggered by the inclusion of the three.d parameter on the mesh statement. The extent in the z-direction is set by the z.mesh statements. The syntax for the remainder of the input is similar to that used in 2D.

Following the completion of the calculation of the Gummel plot for the 3D structure, the characteristics of the two structures are plotted for comparison.

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.