SiGe HBT Fabrication and Characterization Simulation

hbtex05.in : SiGe HBT Fabrication and Characterization Simulation

Requires: SSuprem 4/Blaze
Minimum Versions: Atlas 5.28.1.R

This example demonstrates fabrication and analysis of SiGe HBT. A bipolar device with a SiGe base created in Athena, and then passed to Atlas for electrical analysis to extract a gummel plot and bipolar gain. It shows:

  • SiGe simulation in Athena
  • Specification of donor and acceptor dopants for SiGe material
  • Athena-Atlas automatic interface
  • DC simulation for Ic and Ib versus Vbe

This example contains two parts. The first is the Athena process simulation of the HBT, and the second is the Atlas electrical analysis. The whole of the Atlas part of this example is as described in the first example in this section with the exception of the Atlas structure specification syntax.

The Athena run starts by defining the mesh and the silicon substrate. After the buried collector formation, the structure is flipped upside down using
struct outf=<file>
init inf=<file> flip.y
The next step is the deposition of the silicon germanium layer. SiGe is a recognized material in FLASH so no special syntax is needed. The remainder of the bipolar processing is use of typical process simulation commands for base and emitter implant, silicon emitter layer and various drive steps. Metal contacts are deposited, patterned and defined using the electrode statement.

The key statement required for the Athena/Atlas interface is to define the type of dopants that boron and phosphorus are in SiGe. This is necessary for all materials in FLASH. The command impurity i.boron acceptor sige sets boron as an acceptor-type dopant in SiGe. A similar statement sets phosphorus as a donor-type dopant.

The line go atlas defines the automatic interface with Atlas. In Atlas, no structure specification syntax (including the mesh statement) is needed.

Results of the electrical simulation can be seen in TonyPlot. Ic and Ib plots vs. Vbe can be seen from the log file. The band diagram and other physical variables can be seen from the solution file.

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.