ALD metal oxide deposition process using direct oxidation

• US 7,569,501 B2
• Filed: 05/31/2006
• Issued: 08/04/2009
• Est. Priority Date: 06/14/2002
• Status: Expired due to Fees

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Gopal, Vidyut, Athreya, Shankarram A., Kher, Shreyas S., Han, Shixue, Metzner, Craig R.
• Primary Examiner(s): Kebede; Brook
• Application Number:
  US11/421,293
• Publication Number:
  US 20070059948A1
• Time in Patent Office: 1,161 Days
• Field of Search: 438/758, 438/778, 438/784, 438/785, 438/788, 257/E21.001, 257/E21.006, 427/248.1, 427/249.19, 427/250, 427/252
• US Class Current: 438/785
• CPC Class Codes: C23C 16/405 of refractory metals or yttrium
• CPC Class Codes: C23C 16/452 by activating reactive gas streams before their introduction into the reaction chamber, e.g. by ionisation or addition of reactive species
• CPC Class Codes: C23C 16/45542 Plasma being used non-continuously during the ALD reactions
• CPC Class Codes: C23C 16/45553 characterized by the use of precursors specially adapted for ALD
• CPC Class Codes: H01L 21/02181 the material containing hafnium, e.g. HfO2
• CPC Class Codes: H01L 21/02274 in the presence of a plasma [PECVD]
• CPC Class Codes: H01L 21/0228 deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/31604 Deposition from a gas or vapour H01L21/31691, H01L21/31695 take precedence
• CPC Class Codes: H01L 21/318 composed of nitrides

Abstract

Embodiments of the invention provide methods for forming hafnium materials, such as oxides and nitrides, by sequentially exposing a substrate to hafnium precursors and active oxygen or nitrogen species (e.g., ozone, oxygen radicals, or nitrogen radicals). The deposited hafnium materials have significantly improved uniformity when deposited by these atomic layer deposition (ALD) processes. In one embodiment, an ALD chamber contains an expanding channel having a bottom surface that is sized and shaped to substantially cover a substrate positioned on a substrate pedestal. During an ALD process for forming hafnium materials, process gases form a vortex flow pattern while passing through the expanding channel and sweep across the substrate surface. The substrate is sequentially exposed to chemical precursors that are pulsed into the process chamber having the vortex flow.

Claims

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

positioning a substrate within a process chamber comprising a centralized expanding channel;

flowing a process gas into the centralized expanding channel to form a vortex flow pattern;

exposing the substrate to the process gas having the vortex flow pattern;

exposing the substrate to a hafnium precursor comprising the chemical formula (R′

RN)₄Hf, wherein each R and R′

is independently a hydrogen group or an alkyl group having from one to four carbon atoms;

exposing the substrate to an oxygen precursor; and

exposing the substrate to active nitrogen species.

2. The method of claim 1, wherein the process chamber is pressurized at a pressure of less than about 10 Torr and the substrate is heated to a temperature within a range from about 150°

C to about 225°

C.

3. The method of claim 1, wherein R is an ethyl group.

4. The method of claim 3, wherein the hafnium precursor is TDEAH.

5. The method of claim 1, wherein the oxygen precursor comprises active oxygen species.

6. The method of claim 5, wherein the oxygen precursor further comprises a mixture of argon and oxygen radicals.

7. The method of claim 6, wherein the mixture of argon and oxygen radicals has an argon:

oxygen ratio of 1;

2.

8. A method for forming a hafnium material on a substrate, comprising:

positioning a substrate within a process chamber comprising a centralized expanding channel;

flowing a process gas into the centralized expanding channel to form a vortex flow pattern;

exposing the substrate to the process gas having the vortex flow pattern; and

pulsing a hafnium precursor and an oxygen precursor sequentially into the process gas having the vortex flow pattern to expose the substrate to the hafnium precursor and the oxygen precursor while depositing a hafnium oxide material during an atomic layer deposition process.

9. The method of claim 8, further comprising pulsing a hafnium precursor and a nitrogen precursor sequentially into the process gas having the vortex flow pattern to expose the substrate to the hafnium precursor and the nitrogen precursor while depositing a hafnium nitride material during an atomic layer deposition process.

10. The method of claim 8, further comprising exposing the substrate to active nitrogen species formed by a plasma source.

11. The method of claim 8, wherein the oxygen precursor comprises active oxygen species.

12. The method of claim 11, wherein the oxygen precursor further comprises a mixture of argon and oxygen radicals.

13. The method of claim 12, wherein the mixture of argon and oxygen radicals has an argon:

oxygen ratio of 1;

2.

14. The method of claim 8, wherein the hafnium precursor comprises the chemical formula (R′

RN)₄Hf and each R and R′

is independently a hydrogen group or an alkyl group having from one to four carbon atoms.

15. The method of claim 14, wherein R is an ethyl group.

16. The method of claim 15, wherein the hafnium precursor is TDEAH.

17. A method for forming a hafnium material on a substrate, comprising:

positioning a substrate within a process chamber comprising a centralized expanding channel;

flowing a process gas into the centralized expanding channel to form a vortex flow pattern;

exposing the substrate to the process gas having the vortex flow pattern;

pulsing a hafnium precursor into the process gas having the vortex flow pattern to form a layer of the hafnium precursor on the substrate;

pulsing an oxygen precursor into the process gas having the vortex flow pattern to form an oxide layer thereon;

pulsing the hafnium precursor into the process gas having the vortex flow pattern to form another layer of the hafnium precursor;

pulsing a nitrogen precursor into the process gas having the vortex flow pattern to form a nitride layer thereon.

18. The method of claim 17, wherein the nitrogen precursor comprises active nitrogen species formed by a plasma source.

19. The method of claim 17, wherein the oxygen precursor comprises active oxygen species.

20. The method of claim 17, wherein the hafnium precursor comprises the chemical formula (R′

RN)₄Hf and each R and R′

is independently a hydrogen group or an alkyl group having from one to four carbon atoms.