Pretreatment processes within a batch ALD reactor

• US 7,402,534 B2
• Filed: 08/26/2005
• Issued: 07/22/2008
• Est. Priority Date: 08/26/2005
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Mahajani, Maitreyee
• Primary Examiner(s): Lebentritt; Michael S.
• Assistant Examiner(s): Roman; Angel
• Application Number:
  US11/213,161
• Publication Number:
  US 20070049053A1
• Time in Patent Office: 1,061 Days
• Field of Search: 438/785, 438/758, 438/778, 257/E21.24
• US Class Current: 438/785
• CPC Class Codes: C23C 16/0218 in a reactive atmosphere C23C16/0227 takes precedence
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• CPC Class Codes: C23C 16/45531 specially adapted for making ternary or higher compositions
• CPC Class Codes: C23C 16/45546 specially adapted for a substrate stack in the ALD reactor
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/3141 Deposition using atomic layer deposition techniques [ALD]
• CPC Class Codes: H01L 21/3142 of nano-laminates, e.g. alternating layers of Al203-Hf02

Abstract

Embodiments of the invention provide methods for forming a material on a substrate which includes exposing a plurality of substrates within a batch process chamber to a first oxidizing gas during a pretreatment process, exposing the substrates sequentially to a precursor and a second oxidizing gas during an ALD cycle and repeating the ALD cycle to form a material on the substrates. In a preferred example, a hafnium precursor is used during the ALD process to form a hafnium-containing material, such as hafnium oxide. In one example, the first and second oxidizing gases are the same oxidizing gases. In a preferred example, the first and second oxidizing gases are different oxidizing gases, such that the pretreatment process contains ozone and the ALD process contains water vapor.

Claims

1. A method for forming a hafnium material on a substrate within a process chamber, comprising:

exposing a plurality of substrates within a batch process chamber to a first oxidizing gas during a pretreatment process, wherein the first oxidizing gas comprises an O₃/O₂ mixture having an ozone concentration within a range from about 5 atomic percent to about 30 atomic percent;

exposing the plurality of substrates sequentially to a second oxidizing gas and a process gas containing a hafnium precursor gas during an ALD cycle, wherein the second oxidizing gas comprises water and the hafnium precursor gas comprises a hafnium amino compound; and

repeating the ALD cycle to form a hafnium-containing layer having a thickness within a range from about 5 Å

to about 300 Å

.

2. The method of claim 1, wherein the hafnium-containing layer comprises hafnium oxide.

3. The method of claim 2, wherein the hafnium oxide has the chemical formula of HfO_x, whereas x is about 1.8.

4. The method of claim 1, wherein the plurality of substrates contains at least 25 substrates.

5. The method of claim 1, wherein the process gas further comprises a silicon precursor.

6. The method of claim 5, wherein the hafnium-containing layer comprises hafnium silicate.

7. The method of claim 1, wherein the hafnium amino compound is tetrakis(diethylamino)hafnium, tetrakis(dimethylamino)hafnium, or tetrakis(ethylmethylamino)hafnium.

8. The method of claim 7, wherein the substrate is heated to a temperature within a range from about 200°

C. to about 400°

C. during the ALD cycle.

9. The method of claim 1, wherein the ozone concentration is within a range from about 10 atomic percent to about 20 atomic percent.

10. The method of claim 1, wherein the thickness of the hafnium-containing layer is within a range from about 10 Å

to about 200 Å

.

11. The method of claim 10, wherein the thickness is within a range from about 20 Å

to about 100 Å

.

12. A method for forming a hafnium material on a substrate within a process chamber, comprising:

exposing a substrate within a process chamber to a first oxidizing gas for a predetermined time during a pretreatment process, wherein the first oxidizing gas comprises an O₃/O₂ mixture having an ozone concentration within a range from about 1 atomic percent to about 50 atomic percent;

conducting an ALD cycle, comprising;

exposing the substrate to a hafnium precursor gas comprising a hafnium amino compound for a time period of at least about 30 seconds;

exposing the process chamber to a first purge process;

exposing the substrate to a second oxidizing gas comprising water for a time period of at least about 30 seconds; and

exposing the process chamber to a second purge process; and

repeating the ALD cycle to form a hafnium-containing layer having a thickness within a range from about 5 Å

to about 300 Å

.

13. The method of claim 12, wherein the hafnium precursor gas is exposed to the substrate for a time period within a range from about 30 seconds to about 90 seconds.

14. The method of claim 13, wherein the second oxidizing gas is exposed to of substrate for a time period within a range from about 30 seconds to about 90 seconds.

15. The method of claim 12, wherein the ALD cycle further comprises sequentially exposing the substrate to a silicon precursor and the second oxidizing gas.

16. The method of claim 15, wherein the hafnium-containing layer comprises hafnium silicate.

17. The method of claim 12, wherein the hafnium amino compound is tetrakis(diethylamino)hafnium, tetrakis(dimethylamino)hafnium, or tetrakis(ethylmethylamino)hafnium.

18. The method of claim 17, wherein the substrate is heated to a temperature within a range from about 200°

C. to about 400°

C. during the ALD cycle.

19. The method of claim 12, wherein the ozone concentration is within a range from about 5 atomic percent to about 30 atomic percent.

20. The method of claim 19, wherein the ozone concentration is within a range from about 10 atomic percent to about 20 atomic percent.

21. The method of claim 12, wherein the thickness of the hafnium-containing layer is within a range from about 10 Å

to about 200 Å

.

22. The method of claim 21, wherein the thickness is within a range from about 20 Å

to about 100 Å

.

23. The method of claim 12, wherein the hafnium-containing layer comprises hafnium oxide having the chemical formula of HfO_x, whereas x is about 1.8.

24. A method for forming a hafnium material on a substrate within a process chamber, comprising:

exposing a substrate to water within a process chamber during a pretreatment process;

exposing the substrate sequentially to a hafnium precursor gas and an oxidizing precursor gas during an ALD cycle, wherein the substrate is heated to a temperature within a range from about 200°

C. to about 400°

C. during the ALD cycle, the oxidizing precursor gas comprises an O₃/O₂ mixture having an ozone concentration within a range from about 5 atomic percent to about 30 atomic percent, and the hafnium precursor gas comprises a hafnium amino compound; and

repeating the ALD cycle to form a hafnium-containing layer having a thickness within a range from about 5 Å

to about 300 Å

.

25. The method of claim 24, wherein the pretreatment process occurs for a time period within a range from about 1 second to about 5 minutes.

26. The method of claim 24, wherein the pretreatment process occurs for a time period within a range from about 5 minutes to about 60 minutes.

27. The method of claim 24, wherein the hafnium amino compound is tetrakis(diethylamino)hafnium, tetrakis(dimethylamino)hafnium, or tetrakis(ethylmethylamino)hafnium.

28. The method of claim 27, wherein the temperature is about 200°

C., about 250°

C., or about 300°

C.

29. The method of claim 27, wherein the ozone concentration is within a range from about 10 atomic percent to about 20 atomic percent.

30. The method of claim 24, wherein the thickness of the hafnium-containing layer is within a range from about 10 Å

to about 200 Å

.

31. The method of claim 30, wherein the thickness is within a range from about 20 Å

to about 100 Å

.

32. The method of claim 24, wherein the hafnium-containing layer comprises hafnium oxide having the chemical formula of HfO_x, whereas x is about 1.8.