Method and apparatus for monitoring wafer characteristics and/or semiconductor processing consistency using wafer charge distribution measurements
First Claim
1. A method for processing a substrate, the method comprising the steps of:
- collecting plasma charge data from a surface of the substrate; and
using the plasma charge data to determine etching characteristics of a given process step.
4 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for characterizing processing operations is presented. Following exposure of a wafer to plasma, the surface charge distribution pattern on the wafer is measured. The surface charge distribution pattern on the wafer is then compared with known surface charge distribution patterns to determine if the measured charge distribution pattern correlates to desirable patterns associated with successful performance of one or more processing steps. In some embodiments, the comparison of the measured charge distribution pattern can be used to detect specific problems in one or more processing steps such that corrective action can be taken in a timely manner. The comparison between the measured charge distribution pattern and known charge distribution patterns may be performed using image comparison or using quantitative comparisons based on charge levels measured within each pattern.
53 Citations
40 Claims
-
1. A method for processing a substrate, the method comprising the steps of:
-
collecting plasma charge data from a surface of the substrate; and
using the plasma charge data to determine etching characteristics of a given process step. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
comparing the plasma charge data to reference charge data stored in computer readable medium.
-
-
5. The method of claim 4 wherein the step of using comprises:
comparing the plasma charge data to reference charge data stored in computer readable medium to determine whether the etching characteristics are acceptable.
-
6. The method of claim 5 wherein the etching characteristics include uniformity of an etch rate across the substrate.
-
7. The method of claim 5 wherein the etching characteristics include an etch rate across the substrate.
-
8. The method of claim 5 wherein the etching characteristics include a selectivity of the etch rate across the substrate.
-
9. The method of claim 5 wherein the reference charge data is a collection of data from one or more previous wafers processed using the method.
-
10. The method of claim 5 wherein the reference charge data is a collection of plasma data from a single master reference substrate.
-
11. The method of claim 5 wherein the comparing is performed by comparing an average distribution of charge of the plasma charge data to an average distribution of charge of the reference charge data.
-
12. The method of claim 5 wherein the comparing is performed by comparing a standard deviation of charge in the plasma charge data to a standard deviation of charge in the reference charge data.
-
13. The method of claim 5 wherein the comparing is performed by comparing at least one of a maximum quantity and a minimum quantity of charge in the plasma charge data to at least one of a maximum quantity and a minimum quantity of charge in the reference charge data.
-
14. The method of claim 5 wherein the comparing is performed by segmenting the plasma charge data into first segments of data and segmenting the reference charge data into second segments of data and uniformly processing and comparing data associated with the first and second segments to determine whether the etching characteristics are acceptable.
-
15. The method of claim 14 wherein both the first and second segments are cylindrically assigned based upon position on the substrate in a similar manner.
-
16. The method of claim 14 wherein both the first and second segments are assigned based upon a position on the substrate in a similar rectangular system.
-
17. The method of claim 5 wherein the comparing is performed by an optical pattern recognition process.
-
18. The method of claim 5 wherein the step of comparing results in a comparison value, whereby if the comparison value is within at least one tolerance, the substrate is deemed to be acceptably processed, whereas if the comparison value is outside the at least one tolerance, the substrate is deemed to be unacceptably processed.
-
19. The method of claim 5 wherein the step of comparing is adjusted in accordance with substrate integrated circuit yield data to adjust comparison rules to improve yield.
-
20. The method of claim 5 wherein the method stores the plasma charge data as defective plasma charge data when defective data is encountered by the step of comparing such that, if a similar defective data is encountered in a subsequent comparison operation a probable reason for process failure is determined.
-
21. The method of claim 1 wherein the etching characteristics correspond to etching of a dielectric film on the substrate.
-
22. The method of claim 1 wherein the etching characteristics correspond to etching of a charge retention material on the substrate.
-
23. The method of claim 1 wherein the etching characteristics correspond to etching of a semiconductive film on the substrate.
-
24. The method of claim 1 wherein the etching characteristics correspond to etching of a layer of polymer on the substrate.
-
25. The method of claim 1 wherein collecting the plasma charge data and etching corresponding to the etching characteristics are performed in a processing apparatus that supports both etching and charge data collection.
-
26. The method of claim 1 wherein the etching characteristics are used to determine when a profile of a via has been properly etched.
-
27. The method of claim 1 wherein the etching characteristics are used to determine when a topography of the surface of the substrate is acceptable.
-
28. The method of claim 1 wherein the etching characteristics are used to calibrate an etch chamber to an acceptable initial condition.
-
29. The method of claim 1 wherein the etching characteristics are used to determine microloading etch characteristics associated with etching of a material on the substrate.
-
30. The method of claim 1 wherein the etching characteristics are used to correlate a first etch chamber to a second etch chamber such that both the first and second etch chambers are processing substrates with close consistency.
-
31. A method for processing a substrate, the method comprising the steps of:
-
collecting plasma charge data from a surface of the substrate; and
using the plasma charge data to determine deposition characteristics of a given process step.
-
-
32. A method for processing a substrate, the method comprising the steps of:
-
placing the substrate into a substrate processing tool;
using the substrate processing tool to measure a charge distribution across a surface of the substrate;
selecting a reference charge distribution from among a plurality of reference charge distributions stored in computer readable medium; and
comparing the charge distribution to the reference charge distribution to determine whether the substrate processing tool properly processed the substrate. - View Dependent Claims (33, 34)
storing, when the substrate processing tool improperly processes the substrate, the charge distribution in the computer readable medium as a problem reference charge distribution.
-
-
34. The method of claim 32 further comprising:
comparing, when the substrate processing tool improperly processes the substrate, the charge distribution with one or more problem reference charge distributions stored in the computer readable medium in an attempt to determine if a similar previous failure condition occurred for another substrate.
-
35. A method for processing a set of one or more wafers, the method comprising the steps of:
-
providing a test wafer into a processing tool;
exposing the test wafer to a charge-comprising environment in the processing tool whereby the charge-comprising environment forms a charge pattern on the test wafer;
measuring the charge pattern on the test wafer and using the charge pattern as measured to create a reference charge pattern stored in a computer readable medium;
placing the set of one or more wafers in the processing tool for processing;
exposing one or more of the wafers to the charge-comprising environment whereby the charge-comprising environment forms a charge pattern on the one or more wafers; and
comparing the charge pattern collected from the one or more wafers with the reference charge pattern to determine if the one or more wafers was processed adequately. - View Dependent Claims (36, 37, 38)
-
-
39. A method for processing a substrate, the method comprising the steps of:
-
collecting a plurality of problem charge distribution patterns in computer readable medium and associating each of the problem charge distribution patterns with one or more faults that resulted in that problem charge distribution pattern;
scanning a subsequent monitor wafer to obtain a monitor charge distribution pattern; and
comparing the monitor charge distribution pattern with one or more of the plurality of problem charge distribution patterns via a computer to determine if the monitor charge distribution pattern matches one of the plurality of problem charge distribution patterns whereby process correction may be expedited.
-
-
40. A method for processing a wafer, the method comprising the steps of:
-
placing the wafer into a processing tool having a plurality of chambers;
processing the wafer in a first chamber within the plurality of chambers to charge a surface of the wafer;
moving the wafer into a second chamber within the plurality of chambers, the moving being accomplished without breaking vacuum to atmospheric pressure;
measuring the charge distribution on the surface of the wafer in the second chamber; and
using the charge distribution to perform future process monitoring associated with the processing tool.
-
Specification