The IR20 light sensor provides the signal used to synchronize the In Situ Host algorithm to the operation of the lamp degas process. The IR20 sensor is a simple light sensor with a light filter such that ambient light will not be confused with the light from the degas lamps.
On most tools, this environment is very turbulent, with the loadlocks, cooldown chambers, and preclean chamber providing frequent significant pressure excursions. In addition, the time in which the chemistry evolves from the wafer is critical to the evaluation. Accounting for these factors is necessary for effective automation.
Monitoring Lamp Degas Processes
An infrared light sensor is used to measure the output of the degas lamps. This signal is used to synchronize the analysis to the degas process. On the standard lamp degas reactor design, the output of the lamps is not a closed loop control, only the setpoint is controlled. In addition to providing the synchronization for the in situ analysis, a process control for lamp performance is added.
