Are Sycon instruments compatible with sensors from other manufacturers?

Yes, provided the sensors are designed for a frequency of 6 MHz. Sycon recommends the use of a Sycon oscillator.

For more FAQ information specific to a particular Sycon product, check the Support section of this website.

Why do I see a rate flutter and/or a negative deposition rate for a short time after I open the shutter to my e-beam gun?

The problem is caused by the sensor changing temperature. The crystal sensor acts as a mass measurement device as well as a temperature sensor. As the sensor heats up, the frequency of the sensor increases, and produces a negative rate. The opposite happens when it cools. The heating is usually caused by infrared radiation from the source, or from other sources (like a substrate heater).

In most cases, the frequency shift caused by the deposition of material is much larger than the shift caused by the temperature of the crystal. In some low rate systems the 'temperature shift' is a problem.

Here are some tips to help:
1) Make sure the sensor has good water cooling.
2) Shield the sensor from "stray" radiation. The sensor should "see" the
deposition source and nothing else.
3) Move the sensor away from the sources of thermal interference.

Thickness error is caused by the difference in temperature of the crystal at the time the thickness was zeroed (at the beginning of deposit) vs the crystal temperature at the end of deposit. To minimize the thickness error you need to minimize the difference in these temperatures.