METHOD AND SYSTEM FOR ADVANCED PROCESS CONTROL IN AN ETCH SYSTEM BY GAS FLOW CONTROL ON THE BASIS OF CD MEASUREMENTS

Abstract

By controlling the flow rate of one or more gaseous components of an etch ambient during the formation of metal lines and vias on the basis of feedback measurement data from critical dimensions, process variations may be reduced, thereby enhancing performance and reliability of the respective metallization structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:

FIGS. 1 a-1d schematically illustrates cross-sectional views of a semiconductor device during the formation of vias and trenches in a metallization layer with an etch atmosphere controlled in accordance with illustrative embodiments of the present invention;

FIG. 2 a schematically illustrates a manufacturing environment for patterning a dielectric layer for receiving metal lines and vias coupled to a control system for controlling the etch process in accordance with yet other illustrative embodiments of the present invention;

FIG. 2 b schematically illustrates a control system connected to a manufacturing environment including a plurality of different etch tools according to further illustrative embodiments of the present invention; and

FIGS. 2 c-2d schematically illustrate measurement data for comparing a conventional etch system with an illustrative system according to the present invention.

Claims

1. A method, comprising: etching a first substrate in an etch atmosphere to form a feature above said first substrate, said etch atmosphere being established by supplying at least one gaseous component; andcontrolling a supplying of said at least one gaseous component on the basis of a measured value of a characteristic of said feature on said first substrate when etching in a second etch atmosphere a second substrate to form a feature above said second substrate.

2. The method of claim 1, wherein said features on said first and second substrates are substantially identical.

3. The method of claim 1, wherein said measured value of said characteristic is a value representing a dimension of said feature on said first substrate.

4. The method of claim 1, wherein controlling said supplying of said at least one gaseous component comprises controlling a flow rate of said at least one gaseous component.

5. The method of claim 4, further comprising determining a sensitivity indicating a correlation between said flow rate and said characteristic of said feature on said first substrate.

6. The method of claim 5, wherein controlling said flow rate comprises using said determined sensitivity and said measured value of said characteristic for determining an updated flow rate for etching said second substrate.

7. The method of claim 6, wherein determining said updated flow rate comprises determining a deviation of said measured value from a target value for said characteristic and using said deviation and said sensitivity to determine said updated flow rate.

8. The method of claim 5, wherein said correlation is selected as a linear relationship.

9. A method, comprising: obtaining a measured value of a characteristic of a feature, said feature being formed above a substrate by an etch process in an etch ambient established by supplying at least one precursor according to a specified supply parameter;determining an updated value for said supply parameter on the basis of said measured value and a model of said etch process; andprocessing one or more further substrates in said etch ambient using said updated value to form a corresponding feature above said one or more substrates.

10. The method of claim 9, wherein said model specifies a linear relationship between said characteristic and said supply parameter.

11. The method of claim 9, wherein said characteristic represents at least a critical dimension of said feature.

12. The method of claim 9, wherein said characteristic represents an electrical characteristic of said feature.

13. The method of claim 9, further comprising determining a selectivity value indicating a dependence of said characteristic from said supply parameter.

14. The method of claim 13, wherein said etch process for said substrate and said one or more further substrates is performed in a plurality of etch tools, and said selectivity value is determined for each of said plurality of etch tools.

15. The method of claim 13, wherein said selectivity value is determined individually for each category.

16. The method of claim 9, further comprising assigning a category to each of said substrates and said one or more further substrates, said category being different in at least one of a device design and a process history of a substrate.

17. The method of claim 16, wherein said selectivity value is determined individually for each category.

18. The method of claim 9, wherein determining said updated value of said supply parameter comprises determining a deviation of said measured value from a target value for said characteristic and determining a correction value from said deviation and said model.

19. The method of claim 18, wherein determining said updated value further comprises weighting a plurality of previously used values of said supply parameter to determine a weighted average and determining said updated value on the basis of said correction value and said weighted average.

20. The method of claim 9, wherein said supply parameter represents a flow rate of at least one reactive gas component.

21. A control system, comprising: a control section configured to determine at least one updated manipulated variable of a supply parameter for one or more etch process tools on the basis of a model and a measurement data related to a process output associated with each of said one or more etch process tools.

22. The control system of claim 21, wherein said manipulated variable represents a flow rate of at least one gas used in said one or more etch tools.

23. The control system of claim 21, wherein said control section is configured to receive measurement data of critical dimensions of a feature obtained by an etch process in said one or more etch tools and to determine said updated manipulated variable on the basis of said measurement data and a target value for said critical dimension.

24. The control system of claim 23, wherein said control section is further configured to receive electrical measurement data and to determine said updated manipulated variable on the basis of said electrical measurement data.