Multiple Implant Profile Optimization : Multiple Implant Profile Optimization

Requires: SSuprem 4, OPTIMIZER
Minimum Versions: Athena 5.22.3.R

This example performs optimization of implant doses and energies as well as diffusion temperature in order to obtain a specified boron doping profile as well as pn-junction depth. The target boron profile is a constant doping with concentration of 2e16 all the way from the silicon surface until x=1.0. The target for the pn-junction depth is 1.5 micron.

To load and execute this example, select the Load button.

First, run the example without optimization. From, the TonyPlot profile you will see that boron concentration varies between 2e16 and 5e16 and the pn-junction is around 1.3 microns.

In order to find an optimized solution select Optimizer... from the Main Control menu. The Deckbuild: Optimizer screen will appear in a moment. Select Load File ... from the File menu and then load the special optimizer file from the scrolling Optimizer Load menu.

Preset parameters and targets are included in this file. When you select Parameters from the Mode menu you will find that doses and energies for all 4 implants as well as diffusion temperature are chosen as parameters for optimization.

Boron profile bcurve is chosen as an optimization target. Constant concentrations of 2e16 are set as target values for depths from 0.02 to 1 micron. Then a concentration of 1e16 is set for 1.1 micron. Weights for all these points are set to 1.0. A junction depth of 1.5 microns is an additional point target with a weight of 6.0.

Now you can modify any of these targets and/or parameters. Please refer to Chapter Optimizer in the VWF Interactive Tools Manual.

If you want to run the preset optimization task it is better to slightly relax the default stop criteria as follows:

Select Setup from the Mode menu and increase the maximum error to 20.

After this just select the Optimize button.

After optimization is completed you may execute the TonyPlot which will the plot final optimized profile. After optimization is completed you may copy optimized parameters back to the input deck by selecting Copy to Deck from the Edit menu. After that you can run the optimized deck from the beginning and obtain a Tonyplot of the optimized profile.