CCT System Operation & Monitoring 2

Question 1

A Casper system displays a 'heater fault' alarm during operation. What is the FIRST corrective action a technician should take?

Accepted Answer

Acknowledge the alarm and check the heater current readings

Answer

Acknowledging the alarm and checking heater current confirms whether the fault is a sensor issue or an actual heater failure before taking further action.

Question 2

When monitoring a Casper system, which parameter is the primary indicator of proper gas flow through the process chamber?

Accepted Answer

Mass flow controller (MFC) actual vs. setpoint value

Answer

The MFC actual flow vs. setpoint comparison directly indicates whether the correct amount of process gas is being delivered.

Question 3

During steady-state Casper operation, the process pressure suddenly rises above the setpoint. Which component failure is LEAST likely to cause this condition?

Accepted Answer

Failed turbomolecular pump bearing

Answer

A failed TMP bearing typically causes pump speed loss and reduced pumping capacity, but a bearing failure alone is less immediately likely to spike pressure compared to valve or sensor failures.

Question 4

A technician observes that the RF matching network is unable to reach a reflected power below 20 W during a Casper process run. What should be checked first?

Accepted Answer

Chamber pressure and gas flow rates

Answer

Abnormal chamber pressure or gas flow affects plasma impedance, which directly impacts the RF matching network's ability to minimize reflected power.

Question 5

In Casper system operation, what does a sustained rise in turbomolecular pump temperature indicate?

Accepted Answer

Excessive process gas load or cooling system degradation

Answer

Elevated TMP temperature beyond normal operating range suggests the pump is working harder than intended, often due to high gas load or inadequate cooling.

(CCT) Certified Casper Technician Practice Test

(CCT) Certified Casper Technician Practice Test

CCT System Operation & Monitoring 2