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Factors to Consider When Making Humidity
Measurements
If you are using the 300 mm WaferSense AMS (see page
), which has five humidity/temperature (HT) sensors,
please note that the HT1 sensor is near the center of the wafer (close to the warm electronics), but the other four
sensors (HT2 through HT5) are on the cooler periphery of the wafer. As a result, the HT1 sensor usually returns a
higher temperature reading than HT2
–
HT5, and
—
the key point here
—
also returns a lower RH reading than the
other sensors, as shown in the figure below.
The sections below, tell you how to do the following.
•
Set Go/No-Go Tolerances for humidity
•
Set Triggers for humidity
•
Access other humidity menus and functions
