Wafer de-chucking detection and arcing prevention

A method of damage prevention for a semiconductor processing chamber, the method comprising:

• calculating, by a virtual sensor, a change in imaginary impedance (ΔZI) of a plasma circuit formed when plasma is created inside a processing chamber by a plasma source inside the processing chamber, wherein an electrostatic chuck (ESC) inside the processing chamber is configured to chuck a wafer;
• determining, by the virtual sensor, if the wafer is de-chucked based on the change in imaginary impedance and further based on data from at least a first physical sensor or a second physical sensor;
• and
• performing a damage prevention action responsive to determining that the wafer is de-chucked.

A method comprising:

• calculating, by a virtual sensor, a change in imaginary impedance (ΔZI) of a plasma circuit formed while a plasma is created inside a processing chamber, wherein a wafer is chucked by an electrostatic chuck (ESC) inside the processing chamber;
• determining, by the virtual sensor, if the wafer is de-chucked based on the change in imaginary impedance and further based on data from at least a first physical sensor or a second physical sensor;
• and
• performing a damage prevention action responsive to determining that the wafer is de-chucked.