FORMATION OF BORIDE BARRIER LAYERS USING CHEMISORPTION TECHNIQUES

• US 20070197028A1
• Filed: 04/24/2007
• Published: 08/23/2007
• Est. Priority Date: 06/27/2000
• Status: Active Grant

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Mak, Alfred, Byun, Jeong
• Granted Patent: US 7,501,344 B2
• Time in Patent Office: Days
• US Class Current: 438/656
• CPC Class Codes: C23C 16/38 Borides
• CPC Class Codes: C23C 16/45529 specially adapted for making a layer stack of alternating different compositions or gradient compositions
• CPC Class Codes: C23C 16/45531 specially adapted for making ternary or higher compositions
• CPC Class Codes: C23C 16/45553 characterized by the use of precursors specially adapted for ALD
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76846 Layer combinations

Abstract

In one embodiment, a method for depositing a boride-containing barrier layer on a substrate is provided which includes exposing the substrate sequentially to a boron-containing compound and a tungsten precursor to form a first boride-containing layer during a first sequential chemisorption process, and exposing the substrate to the boron-containing compound, the tungsten precursor, and ammonia to form a second boride-containing layer over the first boride-containing layer during a second sequential chemisorption process. In one example, the tungsten precursor contains tungsten hexafluoride and the boron-containing compound contains diborane. In another embodiment, a contact layer is deposited over the second boride-containing layer. The contact layer may contain tungsten and be deposited by a chemical vapor deposition process. Alternatively, the contact layer may contain copper and be deposited by a physical vapor deposition process. In other examples, boride-containing layers may be formed at a temperature of less than about 500° C.

Claims

1. A method for depositing a boride-containing barrier layer on a substrate, comprising:

exposing a substrate sequentially to a boron-containing compound and a tungsten precursor to form a first boride-containing layer comprising tungsten and boron during a first sequential chemisorption process; and

exposing the substrate to the boron-containing compound, the tungsten precursor, and ammonia to form a second boride-containing layer over the first boride-containing layer during a second sequential chemisorption process.

2. The method of claim 1, wherein the second sequential chemisorption process comprises:

exposing the substrate to the boron-containing compound;

exposing the substrate to the ammonia;

exposing the substrate to the tungsten precursor; and

exposing the substrate to the ammonia.

3. The method of claim 1, wherein the second sequential chemisorption process comprises:

exposing the substrate to the boron-containing compound;

exposing the substrate to the ammonia; and

exposing the substrate to the tungsten precursor.

4. The method of claim 1, wherein the tungsten precursor comprises tungsten hexafluoride.

5. The method of claim 4, wherein the boron-containing compound comprises diborane.

6. The method of claim 5, wherein a contact layer is deposited over the second boride-containing layer.

7. The method of claim 6, wherein the contact layer comprises tungsten and the contact layer is deposited by a chemical vapor deposition process.

8. The method of claim 6, wherein the contact layer comprises copper and the contact layer is deposited by a physical vapor deposition process.

9. The method of claim 1, wherein the first boride-containing layer or the second boride-containing layer is formed at a temperature of less than about 500°

C.

10. The method of claim 9, wherein the temperature is about 400°

C. or less.

11. A method for depositing a boride-containing barrier layer on a substrate, comprising:

exposing a substrate to a boron-containing compound, a tungsten precursor, and ammonia to form a first boride-containing layer during a first sequential chemisorption process; and

exposing the substrate sequentially to the boron-containing compound and the tungsten precursor to form a second boride-containing layer over the first boride-containing layer during a second sequential chemisorption process.

12. The method of claim 11, wherein the first sequential chemisorption process comprises:

exposing the substrate to the boron-containing compound;

exposing the substrate to the ammonia;

exposing the substrate to the tungsten precursor; and

exposing the substrate to the ammonia.

13. The method of claim 11, wherein the first sequential chemisorption process comprises:

exposing the substrate to the boron-containing compound;

exposing the substrate to the ammonia; and

exposing the substrate to the tungsten precursor.

14. The method of claim 11, wherein the tungsten precursor comprises tungsten hexafluoride.

15. The method of claim 14, wherein the boron-containing compound comprises diborane.

16. The method of claim 15, wherein a contact layer is deposited over the second boride-containing layer.

17. The method of claim 16, wherein the contact layer comprises tungsten and the contact layer is deposited by a chemical vapor deposition process.

18. The method of claim 16, wherein the contact layer comprises copper and the contact layer is deposited by a physical vapor deposition process.

19. The method of claim 11, wherein the first boride-containing layer or the second boride-containing layer is formed at a temperature of less than about 500°

C.

20. The method of claim 19, wherein the temperature is about 400°

C. or less.

21. A method for depositing a boride-containing barrier layer on a substrate, comprising:

exposing a substrate sequentially to diborane and tungsten hexafluoride to form a first boride-containing layer comprising tungsten and boron during a first sequential chemisorption process; and

exposing the substrate to the diborane, the tungsten hexafluoride, and ammonia to form a second boride-containing layer over the first boride-containing layer during a second sequential chemisorption process.