Question

There are 4 gauges: a) Bourdon gauge b) Pressure Switch c) Capacitance Manometer d) Thermal conductivity

A CVD tool runs its processes at pressures from 10mTorr to 300mTorr. It needs a very precise control of process pressure. What gauge should be used?

Answer 1

The most suitable pressure gauge for a CVD tool operating between 10mTorr and 300mTorr with high precision is a capacitance manometer, as it provides the accuracy and stability required for semiconductor processes. Option C is correct.

Step-by-step explanation:

The student is inquiring about the most suitable pressure gauge for use in a CVD (Chemical Vapor Deposition) tool that operates within a precise pressure range of 10mTorr to 300mTorr. Among the options provided, the best choice for such a low-pressure range and high precision requirement would likely be a capacitance manometer.

This type of gauge measures pressure by detecting changes in electrical capacitance caused by the movement of a diaphragm due to pressure changes.

Considering the need for very precise control of process pressure, a gauge like the Bourdon gauge or a simple pressure switch would not offer the required sensitivity or precision. On the other hand, a thermal conductivity gauge may not be as accurate in the provided pressure range.

Therefore, the capacitance manometer is often the preferred instrument for such applications in the semiconductors industry due to its accuracy and stability at low pressures.