Chemical-mechanical planarization controller
View Patent ↗The invention provides a model-based control approach to chemical-mechanical planarization (CMP) control. The preferred embodiment comprises mathematical models of the CMP process. These models play a critical role in obtaining superior control performance. Model-based Control Design involves the construction of a dynamic mathematical model of the system to be controlled, e.g. a removal rate model of a CMP system. The model can then be evaluated via computer simulations, and validated using data from the system. The invention provides a method and apparatus that processes in-situ data from a suite of real-time sensors and produces real-time commands to multiple actuators, such as applied pressures, slurry-flow rate, and wafer/pad velocity. A key aspect of the invention is an integrated model-based pressure-temperature-velocity-slurry flow control system that includes many innovations in real-time mode identification, real-time gain estimation, and real-time control.
1. A real-time in-situ model-based chemical-mechanical planarization (CMP) controller, comprising:
a dynamic mathematical model of a CMP system to be controlled in response to in-situ data from a plurality of real-time sensors in said CMP system, said mathematical model comprising any of a physics-based model and an empirical model;
computer simulation means for evaluating said mathematical model; and
means for validating said mathematical model using any of real-time, in-situ data and ex-situ data from said CMP system.
2. The controller of claim 1 , further comprising:
a reduced mathematical model for real-time in-situ CMP system control.
3. The controller of claim 1 , said mathematical model comprising any of:
a real-time removal rate model of a CMP system; and
a real-time thermal model of a CMP system.
4. The controller of claim 1 , wherein modifications of said CMP system can be evaluated with said mathematical model via computer simulation prior to any CMP system modifications.
5. A method for producing a real-time in-situ model-based chemical-mechanical planarization (CMP) controller, comprising the steps of:
generating a dynamic mathematical model of a CMP system to be controlled in response to in-situ data from a plurality of real-time sensors in said CMP system said mathematical model comprising any of a physics-based model and an empirical model;
evaluating said mathematical model with a computer simulation; and
validating said mathematical model using any of real-time in-situ data and ex-situ data from said CMP system.
6. The method of claim 5 , further comprising the step of:
controlling said CMP system in real-time with a reduced mathematical model.
7. The method of claim 6 , said mathematical model comprising any of:
a real-time removal rate model of a CMP system; and
a real-time thermal model of a CMP system.
8. The method of claim 6 , further comprising the step of:
evaluating said CMP system with said mathematical model via computer simulation prior to any CMP system modifications.
9. In a model-based chemical-mechanical planarization (CMP) controller, said model comprising: a dynamic mathematical model of a CMP system to be controlled in real-time, said mathematical model comprising any of a physics-based model, an empirical model, and any combination thereof, said mathematical model produced by open-loop and closed-loop techniques comprising use of both a computer simulation means for evaluating said mathematical model and means for validating said mathematical model using any of real-time, in-situ data and ex-situ data from said CMP system, said controller; and
a reduced mathematical model for CMP system control in response to in-situ data from a plurality of real-time sensors in said CMP system.