IP Library Granted Patent US 7,682,924
Granted Patent B2
US 7,682,924 · App. 11/838,070 · Granted Mar 23, 2010

Methods of forming a plurality of capacitors

Assignee: Micron Technology, Inc.
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Quick Facts
Patent No.
US 7,682,924
App. No.
11/838,070
Granted
Mar 23, 2010
Kind
B2
Abstract

A method of forming a plurality of capacitors includes an insulative material received over a capacitor array area and a circuitry area. The array area comprises a plurality of capacitor electrode openings within the insulative material received over individual capacitor storage node locations. The intervening area comprises a trench. Conductive material is formed within the openings and against a sidewall portion of the trench to less than completely fill the trench. Covering material is formed over an elevationally outer lateral interface of the conductive material within the trench and the insulative material of the circuitry area. The insulative material within the array area is etched with a liquid etching solution effective to expose outer sidewall portions of the conductive material within the array area and to expose the conductive material within the trench. The conductive material within the array area is incorporated into a plurality of capacitors.

Claims (61)

1. A method of forming a plurality of capacitors, comprising:

providing a substrate comprising a capacitor array area, a circuitry area other than the capacitor array area, and an intervening area between the capacitor array area and the circuitry area; an insulative material received over the capacitor array area and the circuitry area, the capacitor array area comprising a plurality of capacitor electrode openings within the insulative material received over individual capacitor storage node locations, the intervening area comprising a trench within the insulative material;

forming conductive material within the capacitor electrode openings and within the trench to line the capacitor electrode openings and the trench to less than completely fill the trench, the conductive material within the trench and the insulative material of the circuitry area having an elevationally outer interface laterally therebetween;

forming covering material atop the interface, over all of the circuitry area, and laterally over an upper portion of inner sidewalls of the conductive material within the trench, the covering material not laterally covering an entirety of the inner sidewalls of the conductive material within the trench;

etching the insulative material within the capacitor array area with a liquid etching solution effective to expose outer sidewall portions of the conductive material within the capacitor array area, said etching of the insulative material beginning while the covering material is received over all of the circuitry area; and

incorporating the conductive material within the capacitor array area into a plurality of capacitors.

2. The method of claim 1 comprising forming the covering material to be non-conformally deposited over the upper portion of the inner sidewalls of the conductive material to have at least two different lateral thicknesses therealong.

3. The method of claim 1 comprising forming the covering material to be of the same composition as that of an elevationally outermost portion of the insulative material.

4. The method of claim 1 comprising forming the covering material to be of different composition from that of an elevationally outermost portion of the insulative material.

5. The method of claim 1 comprising forming the covering material to be insulative.

6. The method of claim 5 comprising forming the covering material to comprise at least one of silicon nitride or undoped silicon dioxide.

7. The method of claim 1 comprising forming the covering material to be conductive.

8. The method of claim 7 comprising forming the covering material to comprise W.

9. The method of claim 1 comprising forming the covering material to be semiconductive.

10. The method of claim 9 comprising forming the covering material to comprise polysilicon .

11. The method of claim 1 comprising forming the covering material to comprise at least one of transparent carbon or amorphous carbon.

12. A method of forming a plurality of capacitors, comprising:

providing a substrate comprising a capacitor array area, a circuitry area other than the capacitor array area, and an intervening area between the capacitor array area and the circuitry area; an insulative material received over the capacitor array area and the circuitry area, the capacitor array area comprising a plurality of capacitor electrode openings within the insulative material received over individual capacitor storage node locations, the intervening area comprising a trench within the insulative material;

forming conductive material within the capacitor electrode openings and within the trench to line the capacitor electrode openings and the trench to less than completely fill the trench, the conductive material within the trench and the insulative material of the circuitry area having an elevationally outer interface laterally therebetween;

forming covering material atop the interface and laterally over an upper portion of inner sidewalls of the conductive material within the trench, the covering material not laterally covering an entirety of the inner sidewalls of the conductive material within the trench, wherein the trench comprises a base, the conductive material being formed to have an upwardly exposed portion that is within the trench over and in contact with the trench base, none of said covering material being in contact with said upwardly exposed portion of conductive material that is over and in contact with the trench base;

etching the insulative material within the capacitor array area with a liquid etching solution effective to expose outer sidewall portions of the conductive material within the capacitor array area; and

incorporating the conductive material within the capacitor array area into a plurality of capacitors.

13. The method of claim 1 comprising forming the covering material to a thickness of from about 50 Angstroms to about 1,000 Angstroms over the interface.

14. The method of claim 1 wherein the upper portion of the inner sidewalls over which the covering material is formed is no greater than 20% of depth of the trench within the insulative material.

15. The method of claim 1 wherein the upper portion of the inner sidewalls over which the covering material is formed is no greater than 10% of depth of the trench within the insulative material.

16. The method of claim 1 wherein the liquid etching solution during the etching of the insulative material also etches at least some of the covering material from the substrate.

17. The method of claim 16 wherein the liquid etching solution during the etching of the insulative material etches less than 10% of the covering material from the substrate.

18. The method of claim 16 wherein the liquid etching solution during the etching of the insulative material etches at least a majority of the covering material from the substrate.

19. The method of claim 16 wherein the liquid etching solution etches all of the covering material from the substrate.

20. The method of claim 19 comprising forming the covering material at least in part by chemical vapor depositing Si 3 N 4 at a temperature of at least 550° C., the Si 3 N 4 being deposited to a thickness of from about 120 Angstroms to about 200 Angstroms.

21. The method of claim 19 comprising forming the covering material at least in part by chemical vapor depositing Si 3 N 4 at a temperature of no greater than 500° C., the Si 3 N 4 being deposited to a thickness of from about 300 Angstroms to about 600 Angstroms.

22. The method of claim 19 wherein all of the insulative material that is etched by the liquid etching solution is etched from the substrate prior to all of the covering material being etched from the substrate.

23. The method of claim 19 wherein all of the covering material is etched from the substrate prior to all of the insulative material that is etched by the liquid etching solution being etched from the substrate.

24. The method of claim 1 wherein the insulative material comprises silicon dioxide comprising at least one of phosphorus and boron, and the liquid etching solution comprises HF.

25. A method of forming a plurality of capacitors, comprising:

providing a substrate comprising a capacitor array area, a circuitry area other than the capacitor array area, and an intervening area between the capacitor array area and the circuitry area; an insulative material received over the capacitor array area and the circuitry area, the capacitor array area comprising a plurality of capacitor electrode openings within the insulative material received over individual capacitor storage node locations, the intervening area comprising a trench within the insulative material;

forming conductive material within the capacitor electrode openings and within the trench to line the capacitor electrode openings and the trench to less than completely fill the trench, the conductive material within the trench and the insulative material of the circuitry area having an elevationally outer interface laterally therebetween;

forming conductive covering material atop the interface;

etching the insulative material within the capacitor array area and the conductive covering material with a liquid etching solution effective to expose outer sidewall portions of the conductive material within the capacitor array area and to remove all of the conductive covering material from the substrate; and

incorporating the conductive material within the capacitor array area into a plurality of capacitors.

26. The method of claim 25 wherein the conductive covering material is formed laterally over an upper portion of inner sidewalls of the conductive material within the trench.

27. The method of claim 26 wherein the conductive covering material does not laterally cover an entirety of the inner sidewalls of the conductive material within the trench.

28. The method of claim 27 comprising forming the conductive covering material to be non-conformally deposited over the upper portion of the inner sidewalls of the conductive material to have at least two different lateral thicknesses therealong.

29. The method of claim 25 comprising forming the conductive covering material to comprise W.

30. The method of claim 25 wherein the trench comprises a base, the conductive material being formed to have a portion over and in contact with the trench base, none of said conductive covering material being in contact with said portion of conductive material that is over and in contact with the trench base.

31. The method of claim 25 wherein all of the insulative material that is etched by the liquid etching solution is etched from the substrate prior to all of the conductive covering material being etched from the substrate.

32. The method of claim 25 wherein all of the conductive covering material is etched from the substrate prior to all of the insulative material that is etched by the liquid etching solution being etched from the substrate.

33. A method of forming a plurality of capacitors, comprising:

providing a substrate comprising a capacitor array area, a peripheral circuitry area other than the capacitor array area, and an intervening area between the capacitor array area and the peripheral circuitry area; a doped silicon dioxide material received over the capacitor array area and the peripheral circuitry area, an insulator layer other than doped silicon dioxide received over the doped silicon dioxide material within the capacitor array area and the circuitry area, the capacitor array area comprising a plurality of capacitor electrode openings within the insulator layer and the doped silicon dioxide material which are received over individual capacitor storage node locations, the intervening area comprising a trench within the insulator layer and the doped silicon dioxide material that completely surrounds the capacitor array area;

forming conductive material within the capacitor electrode openings and within the trench to line the capacitor electrode openings and the trench to less than completely fill the capacitor electrode openings and the trench, the conductive material within the trench and the insulator layer of the circuitry area having an elevationally outer interface laterally therebetween;

forming covering material over the insulator layer atop the interface, over all of the peripheral circuitry area, and laterally over an upper portion of inner sidewalls of the conductive material within the trench, the covering material not laterally covering an entirety of the inner sidewalls of the conductive material within the trench;

forming etch openings through the covering material and the insulator layer within the capacitor array area effective to expose the doped silicon dioxide material within the capacitor array area while leaving elevationally outermost surfaces of the doped silicon dioxide material within the peripheral circuitry area completely covered with the covering material and the insulator layer;

etching the doped silicon dioxide material within the capacitor array area through the etch openings with a liquid etching solution effective to expose outer sidewall portions of the conductive material within the capacitor array area, said etching of the doped silicon dioxide beginning while the covering material is received over all of the peripheral circuitry area; and

incorporating the conductive material within the capacitor array area into a plurality of capacitors.

34. The method of claim 33 wherein the liquid etching solution during the etching of the doped silicon dioxide material also etches at least some of the covering material from the substrate.

35. The method of claim 33 comprising forming the covering material to be non-conformally deposited over the upper portion of the inner sidewalls of the conductive material to have at least two different lateral thicknesses therealong.

36. The method of claim 16 wherein the liquid etching solution during the etching of the insulative material does not etch all of the covering material from the substrate.

37. The method of claim 34 wherein the liquid etching solution during the etching of the doped silicon dioxide material does not etch all of the covering material from the substrate.

38. The method of claim 34 wherein the liquid etching solution etches all of the covering material from the substrate.

39. The method of claim 12 wherein the covering material is received over all of the circuitry area at the beginning of said etching of the insulative material.

40. The method of claim 25 wherein the conductive covering material is received over all of the circuitry area at the beginning of said etching of the insulative material.

Assignments (8)
RELEASE OF SECURITY INTEREST Recorded Nov 12, 2019
From: JPMORGAN CHASE BANK, N.A., AS COLLATERAL AGENT
To: MICRON TECHNOLOGY, INC.; MICRON SEMICONDUCTOR PRODUCTS, INC.
Reel/Frame 051028/0001 →
RELEASE OF SECURITY INTEREST Recorded Oct 9, 2019
From: MORGAN STANLEY SENIOR FUNDING, INC., AS COLLATERAL AGENT
To: MICRON TECHNOLOGY, INC.
Reel/Frame 050937/0001 →
RELEASE OF SECURITY INTEREST Recorded Aug 23, 2018
From: U.S. BANK NATIONAL ASSOCIATION, AS COLLATERAL AGENT
To: MICRON TECHNOLOGY, INC.
Reel/Frame 047243/0001 →
SECURITY INTEREST Recorded Jul 13, 2018
From: MICRON TECHNOLOGY, INC.; MICRON SEMICONDUCTOR PRODUCTS, INC.
To: JPMORGAN CHASE BANK, N.A., AS COLLATERAL AGENT
Reel/Frame 047540/0001 →
CORRECTIVE ASSIGNMENT TO CORRECT THE REPLACE ERRONEOUSLY FILED PATENT #7358718 WITH THE CORRECT PATENT #7358178 PREVIOUSLY RECORDED ON REEL 038669 FRAME 0001. ASSIGNOR(S) HEREBY CONFIRMS THE SECURITY INTEREST. Recorded Jun 8, 2017
From: MICRON TECHNOLOGY, INC.
To: U.S. BANK NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 043079/0001 →
PATENT SECURITY AGREEMENT Recorded Jun 2, 2016
From: MICRON TECHNOLOGY, INC.
To: MORGAN STANLEY SENIOR FUNDING, INC., AS COLLATERAL AGENT
Reel/Frame 038954/0001 →
SECURITY INTEREST Recorded May 12, 2016
From: MICRON TECHNOLOGY, INC.
To: U.S. BANK NATIONAL ASSOCIATION, AS COLLATERAL AGENT
Reel/Frame 038669/0001 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 13, 2007
From: BHAT, VISHWANATH; SHEA, KEVIN R.; GOOD, FARRELL
To: MICRON TECHNOLOGY, INC.
Reel/Frame 019687/0135 →
Continuity (1)
Related Publication 20090047769A1 · Feb 19, 2009