In normal operation, the engineer or operator would load the ST1200 process recipe, load the matching endpoint recipe from the Lightwind library, and then push the process start button.
All additional steps are automatic. If the process is repeated it is not necessary to reload the Lightwind recipe each time.
The Lightwind endpoint system interfaces to the ST1200 in two ways:
Optically, a fiber optic cable links the plasma emissions to a spectrometer and therefore to the endpoint software. Digitally, the ST1200 sends a digital “start” signal to Lightwind where a preselected process recipe is loaded and initialized to watch for an endpoint event. When endpoint is detected Lightwind sends a digital “stop” signal to the tool notifying it the process is complete.
The Lightwind Endpoint SImulator is designed to load a full spectral data file so that different wavelengths can be tested as possible endpoint candidates. Different endpoint algorithms provide choices of techniques that offer the most robust control. It is recommended that endpoint simulations are run on more than one sample to provide a statistically significant sampling of process variation.