Monitoring process for oxide removal

• US 20030017628A1
• Filed: 07/18/2001
• Published: 01/23/2003
• Est. Priority Date: 07/18/2001
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Ding, Peijun, Rengarajan, Suraj, Li, Haojiang
• Granted Patent: US 6,579,730 B2
• Time in Patent Office: Days
• US Class Current: 438/14
• CPC Class Codes: G01N 27/041 of a solid body
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps
• CPC Class Codes: Y10S 438/934 Sheet resistance, i.e. dopant parameters

Abstract

Generally, a method for monitoring a process of removing native oxides from an at least partially exposed layer disposed on a substrate is provided. In one embodiment, a method for monitoring includes disposing the substrate in a process chamber, exposing the at least partially exposed layer to a reactive pre-clean process, removing the substrate from the process chamber and measuring a sheet resistance of the exposed layer. In another embodiment, a method includes disposing the substrate in a process chamber, exposing the at least partially exposed conductive layer to a reactive pre-clean process that comprises an oxide reduction step, removing the substrate from the process chamber, contacting the conductive layer with one or more contact members, measuring a sheet resistance of the exposed conductive layer between the contact members, and comparing the measured resistance to a known value.

Claims

1. A method for monitoring a process of removing native oxides from an at least partially exposed layer disposed on a substrate, the method comprising:

disposing the substrate in a process chamber;

exposing the at least partially exposed layer to a reactive pre-clean process;

removing the substrate from the process chamber; and

measuring a sheet resistance of the exposed layer.

2. The method of claim 1, wherein the step of measuring the sheet resistance further comprises:

contacting the at least partially exposed layer with at least one probe set, the probe set comprising two or more contact members coupled to a resistance meter.

3. The method of claim 1, wherein the step of measuring the sheet resistance further comprises:

contacting the at least partially exposed layer with a plurality of probe sets, each probe set comprising two or more contact members disposed in a spaced-apart relation.

4. The method of claim 3, wherein the step of contacting the exposed layer further comprises:

contacting the exposed layer with a first group of probe sets; and

contacting the exposed layer with a second group of probe sets disposed radially outward from the first group of probe sets.

5. The method of claim 3, wherein the step of measuring the sheet resistance further comprises:

comparing the measured resistance between the first and second groups of probe sets.

6. The method of claim 3, wherein the step of measuring the sheet resistance further comprises:

averaging the measured resistance.

7. The method of claim 1 further comprising:

comparing the measured sheet resistance to a sheet resistance known for the at least partially exposed layer.

8. The method of claim 1, wherein the reactive pre-clean process comprises:

forming a plasma from a gas comprising an inert carrier gas combined with less than about 5 percent hydrogen; and

reducing native copper oxide from the at least partially exposed layer.

9. The method of claim 8, wherein the reactive pre-clean process further comprises:

inductively coupling about 1 to about 1000 Watts to the plasma; and

biasing a substrate support with less than about 100 Watts.

10. A method for monitoring a process of removing native oxides from an at least partially exposed conductive layer disposed on a substrate, the method comprising:

disposing the substrate in a process chamber;

exposing the at least partially exposed conductive layer to a reactive pre-clean process that comprises an oxide reduction step;

removing the substrate from the process chamber;

contacting the conductive layer with two or more contact members;

measuring a sheet resistance of the exposed conductive layer between the contact members; and

comparing the measured resistance to a known value.

11. The method of claim 10, wherein the step of contacting the at least partially exposed conductive layer further comprises:

contacting the exposed conductive layer with at least one probe set, the probe set comprising two or more contact members coupled to a resistance meter.

12. The method of claim 10, wherein the step of contacting the exposed layer further comprises:

contacting the exposed conductive layer with a first group of probe sets; and

contacting the exposed conductive layer with a second group of probe sets disposed radially outward from the first probe set.

13. The method of claim 10, wherein the step of measuring the sheet resistance further comprises:

comparing the measured resistance between the first and second groups of probe sets.

14. The method of claim 10, wherein the step of measuring the sheet resistance further comprises:

averaging the measured resistance.

15. The method of claim 10, wherein the reactive pre-clean process comprises:

forming a plasma from a gas comprising an inert carrier gas combined with less than about 5 percent hydrogen; and

reducing native copper oxide from the exposed conductive layer.

16. The method of claim 15, wherein the reactive pre-clean process comprises:

inductively coupling about 1 to about 1000 Watts to the plasma; and

biasing the substrate support with less than about 100 Watts.

17. The method of claim 10, wherein the conductive layer is aluminum or copper.

20. The method of claim 19, wherein the measured substrate is one of a series of production substrates being processed.

21. The method of claim 19, wherein the measured substrate is a utility substrate.

22. The method of claim 19, wherein the step of measuring the sheet resistance further comprises:

contacting the exposed layer with at least one probe set, the probe set comprising two or more contact members coupled to a resistance meter.

23. The method of claim 22, wherein the step of contacting the exposed layer further comprises:

contacting the exposed layer with a first group of probe sets; and

contacting the exposed layer with a second group of probe sets disposed radially outward from the first probe set.

24. The method of claim 19, wherein the step of measuring the sheet resistance further comprises:

comparing the measured resistance between the first and second groups of probe sets.

25. The method of claim 19, wherein the step of measuring the sheet resistance further comprises:

averaging the measured resistance.

26. The method of claim 19, wherein the reactive pre-clean process comprises:

forming a plasma from a gas comprising an inert carrier gas combined with less than about 5 percent hydrogen; and

reducing native copper oxide from the exposed layer.

27. The method of claim 26, wherein the reactive pre-clean process comprises:

inductively coupling about 1 to about 1000 Watts to the plasma; and

biasing a substrate support with less than about 100 Watts.

18. A method for monitoring a process of removing native copper oxide from an at least partially exposed copper layer disposed on a substrate, the method comprising:

disposing the substrate in a process chamber;

exposing the at least partially exposed copper layer to a reactive pre-clean process that comprises exposing the copper oxide to a plasma formed from a hydrogen comprising gas;

removing the substrate from the process chamber;

contacting the exposed copper layer with two or more contact members;

measuring a sheet resistance of the exposed copper layer between the contact members; and

comparing the measured resistance to a known value.

19. A method for monitoring a process of removing native oxides from an at least partially exposed conductive layer disposed on a substrate, the method comprising:

exposing the exposed conductive layers to a plasma at least partially formed from hydrogen in a first chamber coupled to a processing platform to remove native oxides from the exposed conductive layer;

transferring at least one of a series of substrates exposed to the plasma from the first chamber to a metrology device;

measuring the sheet resistance of the conductive layer; and

comparing the measured sheet resistance to a known value.