Pad conditioner cut rate monitoring

Patent metadata

Field	Value
Publication number	US-11577362-B2
Application number	US-201916294604-A
Country	US
Kind code	B2
Filing date	Mar 6, 2019
Priority date	Mar 14, 2018
Publication date	Feb 14, 2023
Grant date	Feb 14, 2023

Abstract

An apparatus for chemical mechanical polishing includes a platen having a surface to support a polishing pad, a carrier head to hold a substrate against a polishing surface of the polishing pad, a pad conditioner to hold a conditioning disk against the polishing surface, an in-situ polishing pad thickness monitoring system, and a controller. The controller is configured to store data associating each of a plurality of conditioner disk products with a respective threshold value, receive an input selecting a conditioner disk product from the plurality of conditioner disk products, determine a particular threshold value associated with the selected conditioner disk product, receive a signal from the monitoring system, generate a measure of a pad cut rate from the signal, and generate an alert if the pad cut rate falls beyond the particular threshold value.

First claim

What is claimed is:

1. An apparatus for chemical mechanical polishing, comprising:
a platen having a surface to support a polishing pad;
a carrier head to hold a substrate against a polishing surface of the polishing pad;
a pad conditioner to hold a conditioner disk against the polishing surface;
an in-situ polishing pad thickness monitoring system; and
a controller configured to:
prior to replacement of a conditioner disk, store preset data associating each respective conditioner disk product of a plurality of conditioner disk products with a respective wear rate threshold value,
receive a data input that identifies a particular conditioner disk product,
select the particular conditioner disk product from the plurality of conditioner disk products in the stored preset data based on the data input and determine a particular wear rate threshold value corresponding to the particular conditioner disk product based on the stored preset data,
receive a signal from the monitoring system,
generate a measure of a pad wear rate from the signal, and
generate an alert if the pad wear rate falls beyond the particular wear rate threshold value.

2. The apparatus of claim 1 , wherein the in-situ polishing pad thickness monitoring system comprises an electromagnetic induction monitoring system.

3. The apparatus of claim 2 , wherein the electromagnetic induction monitoring system comprises a sensor having a magnetic core held in the platen so as to generate a magnetic field to induce current in a metal layer in the conditioning disk.

4. The apparatus of claim 2 , wherein the electromagnetic induction monitoring system comprises a sensor having a magnetic core held on the pad conditioner so as to generate a magnetic field to induce current in the platen.

5. The apparatus of claim 4 , wherein the pad conditioner comprises an arm extending over the platen and the magnetic core is supported on the arm of the pad conditioner.

6. The apparatus of claim 5 , wherein the arm is configured to perform an oscillatory sweeping motion across the polishing pad.

7. The apparatus of claim 5 , wherein the sensor contacts the polishing pad.

8. The apparatus of claim 1 , wherein the controller is configured to apply a predictive filter to the signal to generate a filtered signal, the filtered signal including a sequence of adjusted values, and wherein the controller is configured to generate the filtered signal includes for each adjusted value in the sequence of adjusted values by
generating at least one predicted value from a sequence of measured values from the signal, and
calculating the adjusted value from the sequence of measured values and the predicted value.

9. The apparatus of claim 8 , wherein the controller is configured to generate the at least one predicted value by generating at least one predicted value from the sequence of measured values using linear prediction.

10. An apparatus for chemical mechanical polishing, comprising:
a platen having a surface to support a polishing pad;
a carrier head to hold a substrate against a polishing surface of the polishing pad;
a pad conditioner to hold a conditioning disk against the polishing surface;
an in-situ polishing pad thickness monitoring system; and
a controller configured to receive a signal from the monitoring system, generate a measure of a pad wear rate from the signal, determine a measure of variability of the pad wear rate over time from the signal, and generate an alert if the measure of variability over time exceeds a threshold.

11. The apparatus of claim 10 , wherein the controller is configured to determine a measure of variable by calculating a standard deviation of the pad wear rate.

12. The apparatus of claim 11 , wherein the controller is configured to calculate the standard deviation in a running window of measurements.

13. The apparatus of claim 10 , wherein the in-situ polishing pad thickness monitoring system comprises an electromagnetic induction monitoring system.

14. The apparatus of claim 13 , wherein the electromagnetic induction monitoring system comprises a sensor having a magnetic core held on the pad conditioner so as to generate a magnetic field to induce current in the platen.

15. The apparatus of claim 14 , wherein the pad conditioner comprises an arm extending over the platen and the magnetic core is supported held on the arm of the pad conditioner.

16. A method of controlling chemical mechanical polishing, comprising:
bringing a substrate into contact with a polishing pad on a platen;
generating relative motion between the polishing pad and the substrate;
conditioning the polishing pad;
monitoring the polishing pad with an in-situ pad thickness monitoring system and generating a signal that depends on a thickness of the polishing pad;
generating a measure of a pad wear rate from the signal;
determining a measure of variability over time of the pad wear rate from the signal; and
generating an alert if the measure of variability over time exceeds a threshold.

17. The method of claim 16 , comprising determining the measure of variability by calculating a standard deviation of the pad wear rate.

18. The method of claim 17 , comprising calculating the standard deviation in a running window of measurements.

Assignees

• Applied Materials Inc

Inventors

• Dhandapani Sivakumar
• Deshpande Sameer
• Fung Jason Garcheung

Classifications

• B24B37/34

  Accessories · CPC title

• B24B37/005 Primary

  Control means for lapping machines or devices · CPC title

• B24B37/20

  Lapping pads for working plane surfaces · CPC title

• B24B53/017

  Devices or means for dressing, cleaning or otherwise conditioning lapping tools · CPC title

• B24B49/105 Primary

  using eddy currents · CPC title