Systems and methods for controlling an etch process

Patent metadata

Field	Value
Publication number	US-10386829-B2
Application number	US-201615266679-A
Country	US
Kind code	B2
Filing date	Sep 15, 2016
Priority date	Sep 18, 2015
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

A system for controlling an etch process includes an etching tool, a metrology tool, and a controller. The etching tool is controllable via a set of control parameters and may execute a plurality of etch recipes containing values of the set of control parameters. The controller may direct the etching tool to execute a plurality of etch recipes on a plurality of metrology targets; direct the metrology tool to generate metrology data indicative of two or more etch characteristics on the plurality of metrology targets; determine one or more relationships between the two or more etch characteristics and the set of control parameters based on the metrology data; and generate, based on the one or more relationships, a particular etch recipe to constrain one of the two or more etch characteristics and maintain the remainder of the two or more etch characteristics within defined bounds.

First claim

What is claimed:

1. A system for controlling an etch process, comprising:
an etching tool, the etching tool controllable via a set of control parameters, the etching tool configured to execute a plurality of etch recipes, wherein an etch recipe of the plurality of etch recipes includes values of the set of control parameters;
a metrology tool; and
a controller communicatively coupled to the etching tool and the metrology tool, the controller including one or more processors, wherein the one or more processors are configured to execute one or more instructions configured to cause the one or more processors to:
direct the etching tool to execute a plurality of etch recipes on a plurality of metrology targets;
direct the metrology tool to generate metrology data indicative of two or more etch characteristics on the plurality of metrology targets;
determine one or more relationships between the two or more etch characteristics and the set of control parameters based on the metrology data; and
generate, based on the one or more relationships, a particular etch recipe to constrain one of the two or more etch characteristics and maintain the remainder of the two or more etch characteristics within defined bounds.

2. The system for controlling an etch process of claim 1 , wherein the set of control parameters includes an etching time.

3. The system for controlling an etch process of claim 1 , wherein the etching tool includes a chamber.

4. The system for controlling an etch process of claim 3 , wherein the set of control parameters includes a pressure of a gas within the chamber.

5. The system for controlling an etch process of claim 3 , wherein the set of control parameters includes a composition of a gas within the chamber.

6. The system for controlling an etch process of claim 1 , wherein the etching tool includes a plasma source.

7. The system for controlling an etch process of claim 6 , wherein the plasma source includes a transformer-coupled plasma source.

8. The system for controlling an etch process of claim 7 , wherein the set of control parameters includes a value of a radio-frequency current to drive the transformer-coupled plasma source.

9. The system for controlling an etch process of claim 7 , wherein the set of control parameters includes a transformer-coupled-capacitive-tuning parameter of the transformer-coupled plasma source.

10. The system for controlling an etch process of claim 1 , wherein the etching tool includes a multi-zone gas distribution assembly.

11. The system for controlling an etch process of claim 10 , wherein the set of control parameters includes a number of zones of the multi-zone gas distribution assembly.

12. The system for controlling an etch process of claim 10 , wherein the set of control parameters includes a gas flow rate of one or more zones of the multi-zone gas distribution assembly.

13. The system for controlling an etch process of claim 10 , wherein the set of control parameters includes a composition of a gas from one or more zones of the multi-zone gas distribution assembly.

14. The system for controlling an etch process of claim 1 , wherein the etching tool includes a sample temperature controller to secure a sample, wherein the sample temperature controller includes one or more zones with independently-controllable temperature.

15. The system for controlling an etch process of claim 14 , wherein the set of control parameters includes a temperature of one or more of the one or more zones of the sample temperature controller.

16. The system for controlling an etch process of claim 1 , wherein the two or more etch characteristics include at least one of a critical dimension uniformity, a sidewall angle, an aspect ratio, an etch rate, an etch selectivity, an aspect-ratio-dependent etch rate, or a pattern loading characteristic.

17. The system for controlling an etch process of claim 1 , wherein the metrology tool comprises:
at least one of an image-based metrology system or a scatterometry-based metrology system.

18. The system for controlling an etch process of claim 1 , wherein the defined bounds of the remainder of the two or more etch characteristics are determined by a user.

19. A system for controlling an etch process, comprising:
an etching tool, the etching tool controllable via a set of control parameters, the etching tool configured to execute a plurality of etch recipes, wherein an etch recipe of the plurality of etch recipes includes values of the set of control parameters;
a metrology tool; and
a controller communicatively coupled to the etching tool and the metrology tool, the controller including one or more processors, wherein the one or more processors are configured to execute one or more instructions configured to cause the one or more processors to:
direct the etching tool to execute a plurality of etch recipes on a plurality of metrology targets;
direct the metrology tool to generate metrology data indicative of two or more etch characteristics on the plurality of metrology targets;
determine one or more relationships between the set of control parameters and the two or more etch characteristics;
generate an empirical process model of the etch process, wherein the empirical process model relates the set of control parameters to the two or more etch characteristics based on the metrology data; and
generate, based on the empirical process model, a particular etch recipe to optimize one of the two or more etch characteristics and maintain the remainder of the two or more etch characteristics within defined bounds.

20. The system for controlling an etch process of claim 19 , wherein the set of control parameters includes an etching time.

21. The system for controlling an etch process of claim 19 , wherein the etching tool includes a chamber.

22. The system for controlling an etch process of claim 21 , wherein the set of control parameters includes a pressure of a gas within the chamber.

23. The system for controlling an etch process of claim 21 , wherein the set of control parameters includes a composition of a gas within the chamber.

24. The system for controlling an etch process of claim 19 , wherein the etching tool includes a plasma source.

25. The system for controlling an etch process of claim 24 , wherein the plasma source includes a transformer-coupled plasma source.

26. The system for controlling an etch process of claim 25 , wherein the set of control parameters includes a value of a radio-frequency current to drive the transformer-coupled plasma source.

27. The system for controlling an etch process of claim 25 , wherein the set of control parameters includes a transformer-coupled-capacitive-tuning parameter of the transformer-coupled plasma source.

28. The system for controlling an etch process of claim 19 , wherein the etching tool includes a multi-zone gas distribution assembly.

29. The system for controlling an etch process of claim 28 , wherein the set of control parameters includes a number of zones of the multi-zone gas distribution assembly.

30. The system for controlling an etch process of claim 28 , wherein the set of control parameters includes a gas flow rate of one or more zones of the multi-zone gas distribution assembly.

31. The system for controlling an etch process of claim 28 , wherein the set of c

Assignees

• Kla Tencor Corp

Inventors

• Zach Franz

Classifications

• H01J37/32174

  Circuits specially adapted for controlling the RF discharge · CPC title

• H01J2237/334

  Etching · CPC title

• H01J2237/3343

  Problems associated with etching · CPC title

• G05B2219/45212

  Etching, engraving, sculpturing, carving · CPC title

• H01J37/32091

  the radio frequency energy being capacitively coupled to the plasma · CPC title