Methods of thin film process

• US 7,939,422 B2
• Filed: 11/29/2007
• Issued: 05/10/2011
• Est. Priority Date: 12/07/2006
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: McClintock, William H., Kao, Chien-Teh, Lu, Xinliang, Chang, Mei, Tang, Jing, Ingle, Nitin K., Zheng, Yi, Yuan, Zheng, Ge, Zhenbin, Banthia, Vikash
• Primary Examiner(s): Smith; Matthew S
• Assistant Examiner(s): JEAN BAPTISTE, WILNER
• Application Number:
  US11/947,674
• Publication Number:
  US 20080182382A1
• Time in Patent Office: 1,258 Days
• Field of Search: 438/435, 438/681, 438/396, 438/424, 438/365, 438/3, 438/643, 438/240, 438/656, 438/648, 438/222, 438/218, 438/221, 438/429, 438/413
• US Class Current: 438/435
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/0217 the material being a silicon nitride not containing oxygen, e.g. SixNy or SixByNz H01L21/02126 and H01L21/0214 take precedence
• CPC Class Codes: H01L 21/3105 After-treatment
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H01L 21/76232 of trenches having a shape other than rectangular or V-shape, e.g. rounded corners, oblique or rounded trench walls H01L21/76229 takes precedence

Abstract

A method for forming a semiconductor structure includes forming a plurality of features across a surface of a substrate, with at least one space being between two adjacent features. A first dielectric layer is formed on the features and within the at least one space. A portion of the first dielectric layer interacts with a reactant derived from a first precursor and a second precursor to form a first solid product. The first solid product is decomposed to substantially remove the portion of the first dielectric layer. A second dielectric layer is formed to substantially fill the at least one space.

Claims

1. A method for forming a semiconductor structure, comprising:

forming a plurality of features across a surface of a substrate, at least one space being between two adjacent features;

forming a first dielectric layer on the features and within the at least one space, wherein the first dielectric layer forms a narrower gap above the opening of the at least one space than a lateral gap deeper within the at least one space;

interacting a portion of the first dielectric layer with a reactant, the reactant derived from a first precursor and a second precursor, to form a first solid product, wherein the solid product comprises material from both the reactant and the first dielectric layer;

decomposing the first solid product to substantially remove the portion of the first dielectric layer; and

forming a second dielectric layer to substantially fill the at least one space.

2. The method of claim 1, wherein forming a plurality of features comprises forming at least a plurality of trenches, conductive lines, openings and transistor gates.

3. The method of claim 1, wherein forming the first dielectric layer comprises forming a silicon oxide layer.

4. The method of claim 1, wherein interacting the portion of the first dielectric layer with a reactant comprises:

ionizing the first precursor and the second precursor; and

interacting the ionized first precursor and the ionized second precursor with the portion of the first dielectric layer.

5. The method of claim 1, wherein the first precursor is ammonia (NH₃) and the second precursor is nitrogen trifluoride (NF₃).

6. The method of claim 1, wherein interacting the portion of the first dielectric layer with the reactant comprises:

interacting the portion of the first dielectric layer with the first precursor and the second precursor.

7. The method of claim 1, wherein the first precursor is ammonia (NH₃) and the second precursor is hydrogen fluoride (HF).

8. The method of claim 1, wherein forming the first dielectric layer comprises forming a silicon nitride layer.

9. The method of claim 8, wherein interacting the portion of the first dielectric layer with a reactant comprises:

ionizing the first precursor and the second precursor; and

interacting the portion of the silicon nitride layer with the ionized first precursor and the ionized second precursor.

10. The method of claim 9, wherein the first precursor is hydrogen (H₂) and the second precursor is nitrogen trifluoride (NF₃).

11. The method of claim 1, wherein decomposing the first solid product comprises thermally treating the first solid product to substantially sublimate the first solid product.

12. The method of claim 1, wherein decomposing the first solid product comprises dissolving the product in a liquid solution.

13. The method of claim 12, wherein the liquid solution comprises water or a polar solvent.

14. The method of claim 1 further comprising forming a liner under the first dielectric layer, wherein an etch selectivity of the first dielectric layer to the liner is about 5:

1 or more.

15. The method of claim 14 further comprising:

interacting a portion of the liner with a reactant derived from a third precursor and a fourth precursor to generate a second solid product; and

decomposing the second solid product to remove the portion of the liner.

16. The method of claim 1 further comprising:

interacting another portion of the first dielectric layer with a reactant derived from a third precursor and a fourth precursor to generate a second solid product; and

decomposing the second solid product to remove the another portion of the first dielectric layer.

17. The method of claim 1, wherein forming the first dielectric layer on the features and within the at least one space has a process pressure of about 600 Torr or more.

18. The method of claim 1, wherein decomposing the first solid product forms an angle between slanted sidewalls of the removed first dielectric layer and a bottom of the removed first dielectric layer about 87°

or less.

19. A method of depositing a dielectric material in a semiconductor structure having a bottom and sidewalls, the method comprising:

forming a first dielectric layer on the bottom and sidewalls of the structure, wherein the layer partially fills the structure and forms a narrower gap above the opening of the structure than a lateral gap deeper within the structure;

interacting a portion of the first dielectric layer with a reactant derived from a first precursor and a second precursor to form a first solid product, wherein the solid product comprises material from both the reactant and the first dielectric layer;

thermally treating the first solid product to substantially sublimate the first solid product and form a slanted opening in the structure; and

forming a second dielectric layer to substantially fill the spaces.

20. The method of claim 19, wherein the structure is a gap, and a first angle formed between the bottom and one of the sidewalls of the gap ranges from about 89°

to about 91°

, and wherein a second angle between a sidewall and bottom of the slanted opening is less than 87°

.

21. The method of claim 20, wherein interacting the portion of the first dielectric layer with a reactant comprises:

forming a plasma from the first precursor and the second precursor; and

interacting the plasma with the portion of the first dielectric layer.

22. The method of claim 21, wherein the first precursor is ammonia (NH₃) and the second precursor is nitrogen trifluoride (NF₃) or hydrogen fluoride (HF).

23. The method of claim 21, wherein interacting the portion of the first dielectric layer with a reactant comprises:

introducing the first precursor and the second precursor into an etch chamber; and

interacting the portion of the first dielectric layer with the first precursor and the second precursor.

24. The method of claim 19, wherein forming the first dielectric layer comprises forming a silicon nitride layer.

25. The method of claim 24, wherein interacting the portion of the first dielectric layer with a reactant comprises:

ionizing the second precursor;

introducing the first precursor and the ionized second precursor into an etch chamber; and

interacting the portion of the silicon nitride layer with the first precursor and the ionized second precursor.