Method and system for controlling the chemical mechanical polishing by using a sensor signal of a pad conditioner
In a system and a method according to the present invention, a sensor signal, such as a motor current signal, from a drive assembly of a pad conditioning system is used to estimate the status of one or more consumables in a CMP system.
1. A method of operating a CMP system, comprising:
obtaining a sensor signal from an electric drive assembly driving a pad conditioner of said CMP system;
estimating a first condition of said pad conditioner and a second condition of a polishing pad in contact with said pad conditioner on the basis of said sensor signal; and
predicting a remaining lifetime of the conditioning surface of said pad conditioner on the
basis of the first estimated condition and a remaining lifetime of the polishing surface of said polishing pad on the basis of the second estimated condition.
2. The method of claim 1 , wherein said sensor signal is indicative of at least one of a revolution of at least one electric motor of said drive assembly and a torque of said at least one motor.
3. The method of claim 2 , wherein estimating said condition of said pad conditioner includes:
establishing reference data for at least one characteristic of said pad conditioner; and
comparing said sensor signal with said reference data.
4. The method of claim 3 , wherein said at least one characteristic includes a frictional force acting between a conditioning surface of said pad conditioner and said polishing pad during operation of said CMP system.
5. The method of claim 1 , further comprising controlling operation of said CMP system on the basis of said sensor signal.
6. The method of claim 5 , wherein controlling operation of said CMP system includes readjusting at least one of a downforce, a polish time and a relative speed between a substrate and a polishing pad on the basis of said sensor signal.
7. The method of claim 5 , wherein controlling operation of said CMP system includes readjusting a drive signal to said drive assembly on the basis of said sensor signal to adjust a conditioning effect.
8. A method of controlling a process sequence including a CMP process, comprising:
obtaining a signal from a conditioner drive assembly of a CMP system, said signal being indicative of at least one of a motor torque and a speed of a motor of said drive assembly;
estimating a condition of a polishing pad of said CMP system on the basis of said signal; and
adjusting at least one process parameter in said process sequence on the basis of said estimated polishing pad condition.
9. The method of claim 8 , wherein said at least one process parameter includes at least one of a downforce exerted between the polishing pad and a polishing head is said CMP system, a polish time and relative speed of a pad and the polishing head.
10. The method of claim 8 , wherein said at least one process parameter includes a deposition specific parameter of a deposition tool arranged upstream of said CMP system.
11. The method of claim 2 , wherein estimating said condition of said polishing pad includes:
establishing reference data for at least one characteristic of said polishing pad; and
comparing said sensor signal with said reference data.
12. The method of claim 8 , further comprising estimating a remaining lifetime of the polishing pad on the basis of said signal.
13. The method of claim 10 , further comprising:
estimating a polishing profile of said polishing pad on the basis of said signal; and
determining the deposition specific parameter to provide a deposition profile of a layer formed using the deposition tool consistent with the estimated polishing profile.