Adjusting a substrate polishing condition

Patent metadata

Field	Value
Publication number	US-9233448-B2
Application number	US-201314034495-A
Country	US
Kind code	B2
Filing date	Sep 23, 2013
Priority date	Sep 24, 2012
Publication date	Jan 12, 2016
Grant date	Jan 12, 2016

Abstract

A polishing apparatus polishes a substrate by moving the substrate and a polishing pad relative to each other. The apparatus includes: an elastic modulus measuring device configured to measure an elastic modulus of the polishing pad, and a polishing condition adjustor configured to adjust polishing conditions of the substrate based on a measured value of the elastic modulus. The polishing conditions include pressure of a retaining ring, arranged around the substrate, exerted on the polishing pad and a temperature of the polishing pad.

First claim

What is claimed is:

1. A method for adjusting a polishing condition, said method comprising:
providing a polishing pad to polish a substrate, a top ring to hold the substrate, and a retaining ring to be arranged around the substrate;
measuring an elastic modulus of the polishing pad; and
adjusting a pressure of the retaining ring exerted on the polishing pad based on a first relationship between a measured value of the elastic modulus and the pressure of the retaining ring.

2. The method for adjusting the polishing condition according to claim 1 , wherein the first relationship is determined in advance by:
preparing the polishing pad,
measuring the elastic modulus of the polishing pad,
setting the pressure of the retaining ring,
polishing a sample substrate,
measuring an amount of rounded edge of the sample substrate,
performing a repeat process of repeating setting of the pressure of the retaining ring at a different value, polishing of the sample substrate, and measuring of the amount of rounded edge,
determining an optimum pressure of the retaining ring at which the amount of rounded edge is minimized under the measured elastic modulus of the polishing pad, and
repeating measuring of the elastic modulus of an another polishing pad, setting of the pressure of the retaining ring at a different value, polishing of another sample substrate, measuring the amount of rounded edge, the repeat process, and determining of the optimum pressure.

3. The method for adjusting the polishing condition according to claim 1 , wherein adjusting of the pressure of the retaining ring exerted on the polishing pad is performed based on the first relationship and a temperature of the polishing pad.

4. The method for adjusting the polishing condition according to claim 3 , wherein the temperature of the polishing pad is regulated such that the elastic modulus becomes equal to a predetermined target value.

5. The method for adjusting the polishing condition according to claim 3 , wherein the temperature of the polishing pad is regulated by bringing a temperature-regulating medium into contact with the polishing pad.

6. The method for adjusting the polishing condition according to claim 5 , wherein the temperature-regulating medium is brought into contact with a plurality of regions of the polishing pad separately.

7. The method for adjusting the polishing condition according to claim 6 , wherein at least one of the plurality of regions is a region that contacts a peripheral portion of the substrate.

8. The method for adjusting the polishing condition according to claim 1 , wherein the measuring an elastic modulus of the polishing pad comprises measuring an elastic modulus of the polishing pad during polishing of the substrate.

9. The method for adjusting the polishing condition according to claim 8 , wherein the measuring an elastic modulus of the polishing pad comprises measuring an elastic modulus of the polishing pad in a region upstream of the substrate with respect to a movement direction of the polishing pad.

10. The method for adjusting the polishing condition according to claim 1 , wherein the measuring an elastic modulus of the polishing pad comprises measuring an elastic modulus of the polishing pad before polishing of the substrate.

11. The method for adjusting the polishing condition according to claim 1 , wherein the measuring an elastic modulus of the polishing pad comprises
applying a force to a surface of the polishing pad to deform the polishing pad,
measuring an amount of deformation of the polishing pad, and
dividing the force by the amount of deformation of the polishing pad to determine the elastic modulus of the polishing pad.

12. The method for adjusting the polishing condition according to claim 3 , wherein the temperature of the polishing pad is determined based on a second relationship between the elastic modulus of the polishing pad and a size of surface steps of the substrate.

13. The method for adjusting the polishing condition according to claim 12 , wherein the second relationship is determined in advance by
preparing a plurality of the polishing pads which have different elastic moduli,
selecting one of the polishing pads,
polishing a sample substrate on the selected one of the polishing pads,
measuring a size of surface steps of the sample substrate,
repeating selecting of one of the polishing pads, polishing of a sample substrate on the selected one of the polishing pads, and measuring of the size of the surface steps of the sample substrate, and
determining an optimum elastic modulus of each of the polishing pads at which the size of the surface steps is minimized.

14. The method for adjusting the polishing condition according to claim 1 , wherein measuring the elastic modulus of the polishing pad comprises blowing a pressurized gas onto the polishing pad to form a recess in the polishing pad and measuring a depth of the recess.

Assignees

• Ebara Corp

Inventors

• Motoshima Yasuyuki
• Maruyama Toru

Classifications

• B24B49/14

  taking regard of the temperature during grinding · CPC title

• B24B9/065

  of thin, brittle parts, e.g. semiconductors, wafers · CPC title

• B24B49/03

  according to the final size of the previously ground workpiece · CPC title

• B24B49/10

  involving electrical means (B24B49/02, B24B49/08 take precedence) · CPC title

• B24B37/015

  Temperature control · CPC title