Method of controlling feature dimensions based upon etch chemistry concentrations

• US 6,352,867 B1
• Filed: 01/05/2000
• Issued: 03/05/2002
• Est. Priority Date: 01/05/2000
• Status: Expired due to Term

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Toprac, Anthony J., Campbell, William Jarrett, Couteau, Terri A.
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): ROCCHEGIANI, RENZO
• Application Number:
  US09/478,181
• Time in Patent Office: 790 Days
• Field of Search: 438/5, 438/6, 438/7, 438/8, 438/9, 438/10, 438/11, 438/12, 438/13, 438/14, 438/15, 438/16, 438/17, 438/18
• US Class Current: 438/8
• CPC Class Codes: H01L 21/32134 by liquid etching only

Abstract

The present invention is directed to a method of controlling the width of a gate electrode based upon the etch rate of a chemical bath. In one illustrative embodiment, the method comprises determining an etching rate for a chemical bath, determining the manufactured width of the gate electrode, and varying the time duration of an etching process performed in the bath depending upon the etch rate of the bath and the width of the gate electrode.

Claims

1. A method, comprising:

measuring a manufactured size of a feature above a semiconducting substrate;

calculating an etch rate for a wet etch bath;

determining a duration of an etch process to be performed in said bath after said feature is formed and to which said feature will be exposed, said determination being based upon said calculated etch rate and said measured manufactured size of said feature; and

performing the etch process in said bath for said determined duration.

2. The method of claim 1, wherein measuring a manufactured size of a feature above a semiconducting substrate comprises measuring a manufactured width of a gate electrode of a transistor.

3. The method of claim 1, wherein measuring a manufactured size of a feature above a semiconducting substrate comprises making a plurality of measurements of multiple gate electrodes on a semiconductor device.

4. The method of claim 1, wherein determining a duration of an etch process to be performed in said bath after said feature is formed and to which said feature will be exposed, said determination being based upon said calculated etch rate and said measured manufactured size of said feature, comprises calculating a duration of an etch process to be performed in said bath after said feature is formed and to which said feature will be exposed, said determination being based upon said calculated etch rate and said measured manufactured size of said feature.

5. The method of claim 1, wherein calculating an etch rate for a wet etch bath comprises calculating an etch rate for a wet etch bath comprised of water, ammonium hydroxide and peroxide.

6. The method of claim 5, wherein measuring a manufactured size of a feature formed above a semiconductor substrate comprises measuring a manufactured width of a gate electrode comprised of polysilicon.

7. The method of claim 6, wherein determining a duration of an etch process to be performed in said bath after said feature is formed and to which said feature will be exposed, said determination being based upon said calculated etch rate and said measured manufactured size of said feature, comprises determining a duration of an etch process to be performed on said gate electrode comprised of polysilicon after said gate electrode is formed based upon the measured manufactured width of said gate electrode and upon a concentration of at least one of said water, ammonium hydroxide and peroxide.

8. The method of claim 1, wherein calculating an etch rate for a wet etch bath comprises calculating an etch rate for a wet etch bath based upon an analysis of the chemistry of said bath.

9. A method, comprising:

measuring a manufactured size of a feature above a semiconducting substrate;

calculating an etch rate for a wet etch bath;

providing said measured manufactured size of said feature and said calculated etch rate to a controller that determines a duration of an etch process to be performed in said bath after said feature is formed and to which said feature will be exposed based upon said calculated etch rate and said measured manufactured size of said feature; and

performing the etch process in said bath for said determined duration.

10. The method of claim 9, wherein measuring a manufactured size of a feature above a semiconducting substrate comprises measuring a manufactured width of a gate electrode of a transistor.

11. The method of claim 9, wherein measuring a manufactured size of a feature above a semiconducting substrate comprises making a plurality of measurements of multiple gate electrodes on a semiconductor device.

12. The method of claim 9, wherein determining a duration of an etch process to be performed in said bath after said feature is formed and to which said feature will be exposed, said determination being based upon said calculated etch rate and said measured manufactured size of said feature, comprises calculating a duration of an etch process to be performed in said bath after said feature is formed and to which said feature will be exposed, said determination being based upon said calculated etch rate and said measured manufactured size of said feature.

13. The method of claim 9, wherein calculating an etch rate for a wet etch bath comprises calculating an etch rate for a wet etch bath comprised of water, ammonium hydroxide and peroxide.

14. The method of claim 13, wherein measuring a manufactured size of a feature formed above a semiconductor substrate comprises measuring a manufactured width of a gate electrode comprised of polysilicon.

15. The method of claim 14, wherein determining a duration of an etch process to be performed in said bath after said feature is formed and to which said feature will be exposed, said determination being based upon said calculated etch rate and said measured manufactured size of said feature, comprises determining a duration of an etch process to be performed on said gate electrode comprised of polysilicon after said gate electrode is formed based upon the measured manufactured width of said gate electrode and upon a concentration of at least one of said water, ammonium hydroxide and peroxide.

16. The method of claim 9, wherein calculating an etch rate for a wet etch bath comprises calculating an etch rate for a wet etch bath based upon an analysis of the chemistry of said bath.

17. A method, comprising:

measuring a manufactured width of a gate electrode formed above a semiconducting substrate;

calculating an etch rate for a wet etch bath;

providing said measured manufactured width of said gate electrode and said calculated etch rate to a controller that determines a duration of an etch process to be performed in said bath after said feature is formed and to which said gate electrode will be exposed based upon said calculated etch rate and said measured manufactured width of said gate electrode; and

performing the etch process in said bath for said determined duration.

18. The method of claim 17, wherein measuring a manufactured width of a gate electrode formed above a semiconducting substrate comprises making a plurality of measurements of multiple gate electrodes on a semiconductor device.

19. The method of claim 17, wherein said controller determines a duration of an etch process to be performed in said bath by calculating a duration of an etch process to be performed in said bath after said gate electrode is formed and to which said gate electrode will be exposed based upon said calculated etch rate and said measured manufactured width of said gate electrode.

20. The method of claim 17, wherein calculating an etch rate for a wet etch bath comprises calculating an etch rate for a wet etch bath comprised of water, ammonium hydroxide and peroxide.

21. The method of claim 20, wherein measuring a manufactured width of a gate electrode formed above a semiconductor substrate comprises measuring a manufactured width of a gate electrode comprised of polysilicon.

22. The method of claim 21, wherein determining a duration of an etch process to be performed in said bath after said feature is formed and to which said feature will be exposed, said determination being based upon said calculated etch rate and said measured manufactured size of said feature, comprises determining a duration of an etch process to be performed on said gate electrode comprised of polysilicon after said gate electrode is formed based upon the measured manufactured width of said gate electrode and upon a concentration of at least one of said water, ammonium hydroxide and peroxide.

23. The method of claim 17, wherein calculating an etch rate for a wet etch bath comprises calculating an etch rate for a wet etch bath based upon an analysis of the chemistry of said bath.

24. A method, comprising:

measuring a concentration of at least one component of a wet etch bath;

calculating an etch rate for the wet etch bath based upon the measured concentration of said at least one component of said wet etch bath;

measuring a manufactured width of a gate electrode formed above a semiconducting substrate;

providing said calculated etch rate and said measured manufactured width of said gate electrode to a controller that determines a duration of an etch process to be performed in said bath after said gate electrode is formed and to which said gate electrode will be exposed based upon said calculated etch rate of said wet etch bath and said measured manufactured width of said gate electrode; and

performing the etch process in said bath for said determined duration.

25. The method of claim 24, wherein measuring a manufactured width of a gate electrode comprises making a plurality of measurements of multiple gate electrodes formed above a semiconducting substrate.

26. The method of claim 24, wherein measuring a concentration of at least one component of a wet etch bath comprises positioning a concentration monitor in said bath and obtaining concentration readings from said monitor.

27. The method of claim 24, wherein said controller determines a duration of an etch process to be performed in said bath after said gate electrode is formed by calculating a duration of an etch process to be performed in said bath after said gate electrode is formed and to which said gate electrode will be exposed based upon said calculated etch rate of said bath and said measured manufactured width of said gate electrode.

28. The method of claim 24, wherein calculating an etch rate for a wet etch bath comprises calculating an etch rate for a wet etch bath comprised of water, ammonium hydroxide and peroxide.

29. The method of claim 24, wherein calculating an etch rate for a wet etch bath comprises calculating an etch rate for a wet etch bath based upon an analysis of the chemistry of said bath.

30. A method, comprising:

measuring a concentration of at least one component of a wet etch bath;

calculating an etch rate for the wet etch bath based upon the measured concentration of said at least one component of said wet etch bath;

measuring a manufactured width of a gate electrode comprised of polysilicon formed above a semiconducting substrate;

providing said calculated etch rate and said measured manufactured width of said gate electrode to a controller that calculates a duration of an etch process to be performed in said bath after said gate electrode is formed and to which said gate electrode will be exposed, said calculation being based upon said calculated etch rate of said wet etch bath and said measured manufactured width of said gate electrode; and

performing the etch process in said bath for said calculated duration.

31. The method of claim 30, wherein measuring a manufactured width of a gate electrode comprises making a plurality of measurements of multiple gate electrodes formed above a semiconducting substrate.

32. The method of claim 30, wherein measuring a concentration of at least one component of a wet etch bath comprises positioning a concentration monitor in said bath and obtaining concentration readings from said monitor.

33. The method of claim 30, wherein calculating an etch rate for a wet etch bath comprises calculating an etch rate for a wet etch bath comprised of water, ammonium hydroxide and peroxide.

34. The method of claim 30, wherein calculating an etch rate for a wet etch bath comprises calculating an etch rate for a wet etch bath based upon an analysis of the chemistry of said bath.