Methods for forming rhodium-based charge traps and apparatus including rhodium-based charge traps

• US 7,989,290 B2
• Filed: 03/23/2009
• Issued: 08/02/2011
• Est. Priority Date: 08/04/2005
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Kraus, Brenda D, Marsh, Eugene P.
• Primary Examiner(s): Such; Matthew W
• Application Number:
  US12/408,920
• Publication Number:
  US 20090173991A1
• Time in Patent Office: 862 Days
• Field of Search: 257/325, 257/E21.179, 257/E21.422, 438257-267
• US Class Current: 438/260
• CPC Class Codes: B22F 2202/13 Use of plasma
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 9/12 starting from gaseous material
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H01L 29/40114 the electrodes comprising a conductor-insulator-conductor-insulator-semiconductor structure
• CPC Class Codes: H01L 29/42332 with the floating gate formed by two or more non connected parts, e.g. multi-particles flating gate
• CPC Class Codes: H01L 29/7881 Programmable transistors with only two possible levels of programmation H01L29/7888 takes precedence

Abstract

Isolated conductive nanoparticles on a dielectric layer and methods of fabricating such isolated conductive nanoparticles provide charge traps in electronic structures for use in a wide range of electronic devices and systems. In an embodiment, conductive nanoparticles are deposited on a dielectric layer by a plasma-assisted deposition process such that each conductive nanoparticle is isolated from the other conductive nanoparticles to configure the conductive nanoparticles as charge traps.

Claims

1. A method of forming an electronic device, the method comprising:

forming a dielectric on a substrate;

after forming the dielectric, forming conductive rhodium-based nanoparticles on the formed dielectric including forming the rhodium in the conductive rhodium-based nanoparticles with a deposition time selected to attain a predetermined retention loss property, the conductive rhodium-based nanoparticles formed by a plasma-assisted deposition process such that each conductive rhodium-based nanoparticle is isolated from the other conductive rhodium-based nanoparticles; and

after forming the conductive rhodium-based nanoparticles, forming a capping dielectric on and contacting the formed conductive rhodium-based nanoparticles, the capping dielectric contacting the dielectric such that the capping dielectric isolates the conductive rhodium-based nanoparticles from conductive elements, wherein the conductive rhodium-based nanoparticles are configured as charge traps.

2. The method of claim 1, wherein forming the rhodium in the conductive rhodium-based nanoparticles with a deposition time selected to attain a predetermined retention loss property includes forming the rhodium in the conductive rhodium-based nanoparticles with a deposition time selected corresponding to a retention loss property of 1 volt or less at 150°

C. at 24 hrs.

3. The method of claim 1, wherein forming conductive rhodium-based nanoparticles comprises forming conductive rhodium oxide nanoparticles.

4. The method of claim 1, wherein forming conductive rhodium-based nanoparticles comprises forming a conductive rhodium nanoparticle covered with a conductive rhodium oxide.

5. The method of claim 4, wherein forming conductive rhodium-based nanoparticles comprises using a (C₅H₅)Rh(CO)₂ precursor.

6. The method of claim 1, wherein forming a capping dielectric comprises forming the capping dielectric with the same material composition as the dielectric.

7. The method of claim 1, wherein forming the dielectric, the conductive rhodium-based nanoparticles on the formed dielectric, the capping dielectric on and contacting the formed conductive rhodium-based nanoparticles includes forming the dielectric, the conductive rhodium-based nanoparticles, and the capping dielectric in a nanolaminate structure.

8. The method of claim 1, wherein the method includes forming the conductive rhodium-based nanoparticles such that a plurality of the conductive rhodium-based nanoparticles are disposed on a first plane and another plurality of the conductive rhodium-based nanoparticles are disposed on a second plane, the second plane intersecting the first plane.

9. The method of claim 1, wherein the method includes annealing the conductive rhodium-based nanoparticles at conditions such that the conductive rhodium-based nanoparticles are increased in size forming isolated agglomerations of particles as isolated enlarged islands of conductive rhodium-based nanoparticles.

10. The method of claim 9, wherein annealing the conductive rhodium-based nanoparticles includes annealing the conductive rhodium-based nanoparticles such that the conductive rhodium-based nanoparticles are increased by a factor of about five.

11. A method of forming an electronic device, the method comprising:

forming a dielectric in an integrated circuit on a substrate in a reaction chamber;

after forming the dielectric, subjecting the dielectric to a plasma using a non-reactive gas;

introducing a rhodium-containing precursor into the reaction chamber while turning off the flow of the non-reactive gas in the reaction chamber and maintaining flow of the rhodium-containing precursor into the reaction chamber such that conductive rhodium nanoparticles are formed on the formed dielectric with each of the conductive rhodium nanoparticles isolated from the other conductive rhodium nanoparticles; and

after forming the conductive rhodium nanoparticles, forming a capping dielectric on and contacting the formed conductive rhodium nanoparticles and contacting the dielectric such that the capping dielectric isolates the conductive rhodium nanoparticles from conductive elements, wherein forming the conductive rhodium nanoparticles is preformed separate from forming the dielectric and from forming the capping dielectric, wherein the conductive rhodium-based nanoparticles are configured as charge traps.

12. The method of claim 11, wherein subjecting the dielectric to a plasma using a non-reactive gas includes using an argon plasma.

13. The method of claim 11, wherein maintaining flow of the rhodium-containing precursor into the reaction chamber includes turning the flow of the rhodium-containing precursor into the reaction chamber off after 2 seconds of flow.

14. The method of claim 11, wherein maintaining flow of the rhodium-containing precursor into the reaction chamber includes limiting the flow of the rhodium-containing precursor into the reaction chamber to 10 seconds of flow or less than 10 seconds of flow.

15. The method of claim 11, wherein the method comprises controlling temperatures of the reaction chamber and the substrate such that the formed conductive rhodium nanoparticles have a size based on the controlled temperatures of the reaction chamber and the substrate.

16. The method of claim 11, wherein forming conductive rhodium nanoparticles includes forming the conductive rhodium nanoparticles such that spacing between the conductive rhodium nanoparticles is at about an effective diameter of a conductive rhodium nanoparticle.

17. The method of claim 11, wherein the method includes annealing the conductive rhodium nanoparticles at conditions such that the conductive rhodium nanoparticles are increased in size forming isolated agglomerations of particles as isolated enlarged islands of conductive rhodium nanoparticles.

18. A method of forming a memory, the method comprising:

forming an array of memory cells on a substrate in a reaction chamber, each memory cell having a charge storage unit structured by;

forming a high-κ

dielectric on the substrate;

after forming the high-κ

dielectric, forming conductive rhodium-based nanoparticles on the formed high-κ

dielectric including forming the rhodium in the conductive rhodium-based nanoparticles with a deposition time selected to attain a predetermined retention loss property, the conductive rhodium-based nanoparticles formed by a plasma-assisted deposition process such that each conductive rhodium-based nanoparticle is isolated from the other conductive rhodium-based nanoparticles; and

after forming the conductive rhodium-based nanoparticles, forming a capping dielectric on and contacting the formed conductive rhodium-based nanoparticles and contacting the high-κ

dielectric such that the capping dielectric isolates the conductive rhodium-based nanoparticles from conductive elements, wherein the conductive rhodium-based nanoparticles are configured as charge traps.

19. The method of claim 18, wherein forming the rhodium in the conductive rhodium-based nanoparticles with a deposition time selected to attain a predetermined retention loss property includes forming the rhodium in the conductive rhodium-based nanoparticles with a deposition time selected corresponding to a retention loss property of 1 volt or less at 150°

C. at 24 hrs.

20. The method of claim 18, wherein forming a high-κ

dielectric on the substrate includes forming a HfO_x dielectric.

21. The method of claim 18, wherein forming conductive rhodium-based nanoparticles includes forming rhodium nanoparticles and oxidizing the formed rhodium nanoparticles.

22. The method of claim 18, wherein forming conductive rhodium-based nanoparticles includes forming a rhodium nanoparticle with rhodium oxide covering the formed rhodium nanoparticle.

23. The method of claim 18, the method comprises controlling deposition times of rhodium in a plasma enhanced chemical vapor deposition such that the formed conductive rhodium-based nanoparticles have a density based on the controlled deposition times.

24. A method comprising:

forming a dielectric stack on a substrate;

after forming the dielectric stack, forming conductive rhodium-based nanoparticles on the formed dielectric stack including forming the rhodium in the conductive rhodium-based nanoparticles with a deposition time selected to attain a predetermined retention loss property, the conductive rhodium-based nanoparticles formed by a plasma-assisted deposition process such that each conductive rhodium-based nanoparticle is isolated from the other conductive rhodium-based nanoparticles;

after forming the conductive rhodium-based nanoparticles, forming a capping dielectric on and contacting the formed conductive rhodium-based nanoparticles and contacting the dielectric such that the capping dielectric isolates the conductive rhodium-based nanoparticles from conductive elements, wherein the conductive rhodium-based nanoparticles are configured as charge traps; and

forming a conductive element over the capping dielectric, the conductive element arranged such that the conductive element operatively controls the conductive rhodium-based nanoparticles as charge storage elements.

25. The method of claim 24, wherein forming the rhodium in the conductive rhodium-based nanoparticles with a deposition time selected to attain a predetermined retention loss property includes forming the rhodium in the conductive rhodium-based nanoparticles with a deposition time selected corresponding to a retention loss property of 1 volt or less at 150°

C. at 24 hrs.

26. The method of claim 24, wherein forming a dielectric stack includes forming a HfO_x layer.

27. The method of claim 24, wherein forming a dielectric stack includes forming a silicon oxide layer.

28. The method of claim 24, wherein forming a dielectric stack includes forming the dielectric stack as a nanolaminate.

29. The method of claim 24, wherein forming conductive rhodium-based nanoparticles includes forming rhodium nanoparticles without rhodium oxide in the charge storage elements.

30. The method of claim 24, wherein forming conductive rhodium-based nanoparticles includes forming rhodium oxide.