TRANSFORMING METROLOGY DATA FROM A SEMICONDUCTOR TREATMENT SYSTEM USING MULTIVARIATE ANALYSIS

• US 20090094001A1
• Filed: 12/16/2008
• Published: 04/09/2009
• Est. Priority Date: 02/07/2006
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Timbre Technologies Incorporated (Tokyo Electron Limited)
• Inventors: CHEN, Yan, BAO, Junwei, HEIKO, Weichert, VUONG, Vi, EGRET, Sebastien
• Granted Patent: US 8,170,833 B2
• Time in Patent Office: Days
• US Class Current: 702/189
• CPC Class Codes: G01N 2021/215 Brewster incidence arrangement
• CPC Class Codes: G01N 21/211 Ellipsometry optical thickness measurement G01B11/06
• CPC Class Codes: G01N 21/4788 Diffraction for sizing particles G01N15/0205

Abstract

Metrology data from a semiconductor treatment system is transformed using multivariate analysis. In particular, a set of metrology data measured or simulated for one or more substrates treated using the treatment system is obtained. One or more essential variables for the obtained set of metrology data is determined using multivariate analysis. A first metrology data measured or simulated for one or more substrates treated using the treatment system is obtained. The first obtained metrology data is not one of the metrology data in the set of metrology data earlier obtained. The first metrology data is transformed into a second metrology data using the one or more of the determined essential variables.

Claims

1. A material processing system, comprising:

a treatment system configured to facilitate a treatment process for treating a substrate;

a controller coupled to said treatment system, and configured to perform at least one of monitoring, measuring, adjusting, or controlling process data for performing said treatment process in said treatment system;

a metrology system configured to measure metrology data from said substrate following said treatment process performed in said treatment system, wherein said metrology system comprises an optical metrology system; and

a data processing system coupled to said controller and said metrology system, and configured to interact with said controller and said metrology system and characterize inter-relationships between said process data from said controller and said metrology data from said metrology system using multivariate analysis, wherein said metrology data includes one or more diffraction signals measured from illuminating a structure on said substrate using said metrology system.

2. The material processing system of claim 1, wherein said treatment system comprises an etch system or a track system.

3. The material processing system of claim 1, wherein said metrology system comprises an ellipsometer, reflectometer, or optical digital profilometer.

4. The material processing system of claim 1, wherein said data processing system comprises:

an essential variable processor configured to determine one or more essential variables using multivariate analysis of said metrology data, and utilize at least one of said one or more essential variables to transform said metrology data into refined metrology data.

5. The material processing system of claim 4, wherein said essential variable processor is configured to determine said one or more essential variables using Principal Components Analysis of a set of metrology data acquired for variations in said process data, and utilize at least one of said one or more essential variables to transform additional metrology data into said refined metrology data by computing a vector product of said at least one of said one or more essential variables and said additional metrology data.

6. The material processing system of claim 4, further comprising:

a variable analyzer configured to validate said one or more essential variables by computing one or more statistics associated with an explanation of said metrology data by said one or more essential variables.

7. The material processing system of claim 4, wherein said data processing system comprises:

a pre-processor configured to receive said metrology data from said metrology system and said process data from said treatment system, and exchange said metrology data and said process data with said essential variable processor.

8. The material processing system of claim 7, wherein said pre-processor is configured to center said metrology data, or normalize said metrology data, or both center and normalize said metrology data.

9. The material processing system of claim 7, wherein said pre-processor is configured to set one or more termination criteria for said multivariate analysis of said metrology data, and wherein setting said one or more termination criteria comprise setting a minimum number of said one or more essential variables, setting a maximum number of said one or more essential variables, or setting one or more statistical parameters for a fraction of variance in said metrology data to be explained by said one or more essential variables.

10. The material processing system of claim 9, further comprising:

a comparator configured to determine whether said one or more termination criteria is achieved.

11. The material processing system of claim 9, further comprising:

an adjuster configured to adjust said one or more termination criteria, one or more analysis objectives, or said multivariate analysis, or any combination of two or more thereof.

12. The material processing system of claim 4, further comprising:

a pattern recognition system configured to identify at least one of said one or more essential variables.

13. The material processing system of claim 4, further comprising:

an essential variable verifier configured to perform an accuracy check, or a repeatability check, or both on said utilization of said at least one of said one or more essential variables.

14. A method for operating a treatment system, comprising:

collecting metrology data from one or more substrates treated by a treatment process in said treatment system;

setting objectives for an analysis of said treatment process and said metrology data;

selecting one or more termination criteria for performing said analysis;

determining one or more essential variables from said metrology data using multivariate analysis;

validating said one or more essential variables by computing one or more statistics associated with the explanation of said metrology data by said one or more essential variables;

determining whether said one or more termination criteria is achieved;

adjusting said one or more termination criteria, or said analysis objectives, or said multivariate analysis, or any combination of two or more thereof if said one or more termination criteria are not achieved;

identifying at least one of said one or more essential variables using one or more pattern recognition techniques;

utilizing said at least one of said one or more essential variables to characterize said treatment process, or adjust said treatment process, or monitor said treatment process, or control said treatment process, or detect a fault in said treatment process, or a combination of two or more thereof; and

performing an accuracy check, or repeatability check, or both on said utilization of said at least one of said one or more essential variables.

15. The method of claim 14, wherein said collecting said metrology data comprises collecting optical metrology data.

16. The method of claim 15, wherein said collecting said optical metrology data comprises collecting an optical signal resulting from illuminating one or more structures on said one or more substrates with an incident optical signal.

17. The method of claim 16, wherein said one or more structures includes a periodic structure or a non-periodic structure on said one or more substrates.

18. The method of claim 16, wherein said one or more structures includes one or more periodic structures formed proximate to or on scribe lines on said one or more substrates, said one or more structures includes an operating structure on said one or more substrates.

19. The method of claim 14, wherein said collecting said metrology data comprises collecting a plurality of diffraction signals from optical illumination of said one or more substrates.

20. The method of claim 14, wherein said using multivariate analysis comprises using a linear analysis or a nonlinear analysis.

21. The method of claim 14, wherein said determining one or more essential variables comprises calculating one or more principal components from a set of said metrology data using principal components analysis (PCA).

22. The method of claim 16, wherein said identifying at least one of said one or more essential variables using one or more pattern recognition techniques comprises determining a relationship between said refined metrology data and process performance data related to the profile of said one or more structures on said one or more substrates.

23. A treatment system for preparing a lithographic structure on a substrate, comprising:

a track system configured to coat one or more substrates with a film of light-sensitive material, and develop a pattern in said film of light-sensitive material following exposure of said film of light-sensitive material to radiation;

an exposure system coupled to said track system, and configured to expose said film of light-sensitive material to radiation;

a metrology system to measure a set of metrology data for said one or more substrates treated in said track system and said exposure system for variations in process data for said track system and said exposure system, wherein said process data comprises an exposure focus in said exposure system, an exposure dose in said exposure system, a temperature of a post-application bake of said layer of light-sensitive material preceding said exposure, or a temperature of a post-exposure bake of said layer of light-sensitive material following said exposure, or any combination of two or more thereof;

a data processing system configured to;

obtain said set of metrology data;

determine one or more essential variables for said obtained set of metrology data using multivariate analysis;

obtain new metrology data measured using said metrology system; and

transform said new metrology data into refined metrology data using said one or more essential variables.

24. The treatment system of claim 23, wherein said data processing system is further configured to:

correlating at least one of said one or more essential variables with a critical dimension of said lithographic structure formed in said layer of light-sensitive material following treatment in said track system and said exposure system; and

selecting said at least one of said one or more essential variables that correlates with said critical dimension to transform said new metrology data.

25. The treatment system of claim 23, further comprising:

a controller coupled to said track system, or said exposure system, or both, and configured to control said track system, or said exposure system, or both using refined metrology data.

26. The treatment system of claim 23, wherein said metrology system comprises an optical metrology system, and wherein said multivariate analysis comprises principal components analysis (PCA).

27. A treatment system for etching a feature into a substrate, comprising:

an etching system configured to etch a pattern in one or more substrates using a lithographic structure prepared in a film of light-sensitive material to radiation;

a metrology system to measure a set of metrology data for said one or more substrates treated in said etching system for variations in process data for said etching system, wherein said process data comprises a gas pressure in said etching system, a flow rate of a process gas into said etching system, a power coupled to said process gas in said etching system, a time for performing an etching process in said etching system, a temperature of said one or more substrates, or a temperature of a substrate holder for supporting said one or more substrates, or any combination of two or more thereof;

a data processing system configured to;

obtain said set of metrology data;

determine one or more essential variables for said obtained set of metrology data using multivariate analysis;

obtain new metrology data measured using said metrology system; and

transform said new metrology data into refined metrology data using said one or more essential variables.

28. The treatment system of claim 27, wherein said data processing system is further configured to:

correlating at least one of said one or more essential variables with a critical dimension of said pattern; and

selecting said at least one of said one or more essential variables that correlates with said critical dimension to transform said new metrology data.

29. The treatment system of claim 27, wherein said metrology system comprises an optical metrology system, and wherein said multivariate analysis comprises principal components analysis (PCA).

30. The treatment system of claim 27, further comprising:

a controller coupled to said etching system, and configured to control said etching system using refined metrology data.