Measurement and control of plasma etching in plasma etcher

Because the process variables in plasma etcher process, such as etching rate, pressure, temperature, plasma impedance, etc., are not easy to measure, virtual measurement (Virtual Metrology)

Optical emission spectroscopy

Plasma impedance monitoring

End-point detection

Remote-coupled sensing run-to-run control (R2R)

Model predictive control (MPC)

Artificial neural network control 1. Verify that the multimeter works normally and the range is 200 mV.

2. The cold probe connects the positive electrode of the voltmeter, and the hot probe connects the negative electrode of the voltmeter.

3. Contact a silicon wafer with cold and hot probes at two points which are not connected at the edge. Voltmeter shows that the voltage between these two points is positive, indicating that the conductive type is P-type and the etching is qualified. The same method detects whether the other three edges are P-shaped.

4. If any edge of silicon wafer is not qualified after inspection, the wafers need to be repackaged and etched.