Trench Isolation Punchthrough : Trench Isolation Punchthrough

Requires: SSuprem 4/Elite/S-Pisces
Minimum Versions: Athena 5.22.1.R, Atlas 5.22.1.R

This examples demonstrates punchthrough between unrelated n+ regions separated by trench isolation. It shows:

  • Trench formation by ELITE physical etch models
  • Trench doping using SSUPREM4 implant models
  • Trench fill by ELITE physical deposition models
  • Punchthrough test across the trench using Atlas

The example file consists of two parts. The first uses Athena to construct the geometry and doping of two n+ areas separated by trench isolation. The second uses Atlas to simulate punchthrough between these two regions.

Details of ELITE and SSUPREM4 syntax for trench formation and refill can be found in the appropriate Athena example sections.

The trench is formed by Reactive Ion Etching (RIE), with different isotropic and anisotropic etch rates for each material present. A field implant is performed directly into the trench.

The device is interfaced automatically into Atlas. The two carrier mode is selected along with impact ionisation. The contact named drain is ramped to 20 volts under the control of a current compliance limit of 3e-12 A/um.

The final drain current contours are plotted at the end of the simulation, where the current density can be seen to avoid the field implant doping peak.

A design parameter is measured at the end of the Atlas simulation using the extract statement. The parameter is defined as the voltage required on the drain to get 2e-12 A/um of drain current.

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