real-time process control

**Real-Time Process Control** is the **continuous adjustment of process parameters during wafer processing based on real-time sensor feedback** — using in-situ measurements and closed-loop algorithms to maintain optimal process conditions throughout each run. **How Does Real-Time Control Work?** - **Sensors**: In-situ measurements (temperature, pressure, optical emission, reflectometry, mass spec). - **Algorithm**: PID controller, model predictive control (MPC), or advanced control calculates corrections. - **Actuation**: Adjusts process parameters (power, gas flow, temperature) in real time. - **Examples**: Etch endpoint detection (stop when film clears), ALD temperature compensation. **Why It Matters** - **Within-Wafer Control**: Adjusts parameters during the process to compensate for real-time variations. - **Endpoint Detection**: Precisely stops etch or CMP at the correct thickness. - **Fastest Correction**: No delay — corrections are applied during the same wafer process. **Real-Time Process Control** is **steering the process while it runs** — using live sensor feedback to maintain optimal conditions without waiting for post-process measurements.