Calibration of Thin WetO2 Oxidation

ancaex03.in : Calibration of Thin WetO2 Oxidation

Requires: SSuprem 4, OPTIMIZER
Minimum Versions: Athena 5.21.2.R

This example performs calibration of thin oxide model parameters using OPTIMIZER. These parameters are quite accurately characterized for dryo2 ambient, but virtually no information exists for wetO2 ambient. Historically, wet oxidation has been predominantly used for thick oxide growth. However, low temperature, low pressure, short time wet oxidation is becoming more popular. Unfortunately, to the best of our knowledge extensive experimental results do not exist for such oxidations. Therefore, calibration based just on few experimental points may need to be performed for wet thin oxidations.

The default value for thin oxidation term for wetO2 is zero. This usually underestimates thin oxide thickness. The default values result in 71 A and 173 A oxide thicknesses for 30 and 90 minutes wetO2 oxidation at 820 C and pressure of 0.2 atmospheres. Typical experimental values could be 100 A and 230 A. These values are selected as targets for calibration procedure. Only using OPTIMIZER could the parameters of thin oxidation models be found.

To load and execute this example, select the Load example button. Once loaded, select Optimizer... from the Main Control menu. The Deckbuild: Optimizer screen will appear. Select Load File ... from the File menu and then load the special optimizer file ancaex03.opt 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 thinox.0 and thinox.l are chosen as parameters for optimization. The default values for dryo2 oxidation are selected as an initial guess.

Oxide thicknesses tox1 and tox2 after 30 and 90 minutes of oxidation respectively are selected as a targets.

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 improve the default stop criteria as follows:

Select Setup from the Mode menu. Then decrease the maximum error down to 2, and increase the number of Iterations to 10.

After this just select the Optimize button, on the OPTIMIZER menu.