IP Library Granted Patent US 11,075,274
Granted Patent B2
US 11,075,274 · App. 16/251,307 · Granted Jul 27, 2021

Conductive line construction, memory circuitry, and method of forming a conductive line construction

Inventors: Kenichi Kusumoto (Hiroshima, JP); Yasutaka Iuchi (Hiroshima, JP); Akie Shimamura (Hiroshima, JP)
Assignee: Micron Technology, Inc.
H01L29/4941H01L21/28061H01L29/42372
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Quick Facts
Patent No.
US 11,075,274
App. No.
16/251,307
Granted
Jul 27, 2021
Kind
B2
Abstract

A method of forming a conductive line construction comprises forming a structure comprising polysilicon-comprising material. Elemental titanium is directly against the polysilicon of the polysilicon-comprising material. Silicon nitride is directly against the elemental titanium. Elemental tungsten is directly against the silicon nitride. The structure is annealed to form a conductive line construction comprising the polysilicon-comprising material, titanium silicide directly against the polysilicon-comprising material, elemental tungsten, TiSi x N y between the elemental tungsten and the titanium silicide, and one of (a) or (b), with (a) being the TiSi x N y is directly against the titanium silicide, and (b) being titanium nitride is between the TiSi x N y and the titanium silicide, with the TiSi x N y being directly against the titanium nitride and the titanium nitride being directly against the titanium silicide. Structure independent of method is disclosed.

Claims (48)

1. A method of forming a conductive line construction, comprising:

forming a structure comprising polysilicon-comprising material, elemental titanium directly against the polysilicon of the polysilicon-comprising material, silicon nitride directly against the elemental titanium, and elemental tungsten directly against the silicon nitride; and

annealing the structure to form a conductive line construction comprising:

the polysilicon-comprising material;

titanium silicide directly against the polysilicon-comprising material;

elemental tungsten;

TiSi x N y between the elemental tungsten and the titanium silicide; and

one of (a) or (b), where,

(a): the TiSi x N y is directly against the titanium silicide;

(b): titanium nitride is between the TiSi x N y and the titanium silicide, the TiSi x N y being directly against the titanium nitride, the titanium nitride being directly against the titanium silicide.

2. The method of claim 1 comprising forming the silicon nitride to be amorphous.

3. The method of claim 1 comprising forming all of the silicon nitride at a temperature of no greater than 350° C.

4. The method of claim 1 comprising:

forming the polysilicon-comprising material, the elemental titanium, the silicon nitride, and the elemental tungsten over a substrate; and

forming each of the elemental titanium, the silicon nitride, and the elemental tungsten over the substrate in sub-atmospheric conditions; the substrate being kept at sub-atmospheric conditions at all times between forming all of the elemental titanium and forming all of the elemental tungsten.

5. The method of claim 4 comprising forming the silicon nitride by physical vapor deposition at a temperature of no greater than 350° C.

6. The method of claim 1 wherein the annealing comprises a temperature of at least 800° C.

7. The method of claim 1 comprising forming the elemental titanium to a thickness of 15 Angstroms to 30 Angstroms.

8. The method of claim 1 comprising forming the silicon nitride to a thickness of 25 Angstroms to 40 Angstroms and forming the TiSi x N y to a thickness of 20 Angstroms to 70 Angstroms.

9. The method of claim 1 wherein the annealing forms the TiSi x N y directly against the elemental tungsten.

10. The method of claim 1 wherein the annealing leaves the silicon nitride at a thickness of no more than 10 Angstroms between the TiSi x N y and the elemental tungsten, the TiSi x N y being directly against the silicon nitride of thickness of no more than 10 Angstroms, the elemental tungsten being directly against the silicon nitride of thickness of no more than 10 Angstroms.

11. The method of claim 1 being (a).

12. The method of claim 11 only being the (a) of the (a) and the (b).

13. The method of claim 1 being (b).

14. The method of claim 13 only being the (b) of the (a) and the (b).

15. A method comprising:

forming a structure comprising polysilicon-comprising material, titanium-comprising material over the polysilicon-comprising material, material consisting essentially of silicon nitride over the titanium-comprising material, and tungsten-comprising material over the material consisting essentially of silicon nitride; and

annealing the structure to cause at least a part of the silicon nitride to be converted into conductive material comprising titanium, silicon and nitrogen.

16. A conductive line construction comprising:

polysilicon-comprising material;

a metal silicide directly against the polysilicon of the polysilicon-comprising material;

elemental tungsten;

TiSi x N y between the elemental tungsten and the metal silicide; and

titanium nitride being between the TiSi x N y and the metal silicide, the TiSi x N y being directly against the titanium nitride, the titanium nitride being directly against the metal silicide.

17. A method comprising:

forming a structure comprising polysilicon-comprising material, titanium-comprising material over the polysilicon-comprising material, silicon nitride-comprising material over the titanium-comprising material, and tungsten-comprising material over the silicon nitride-comprising material, the silicon nitride-comprising material being in the structure as amorphous silicon nitride-comprising material; and

annealing the structure to cause at least a part of the silicon nitride to be converted into conductive material comprising titanium, silicon and nitrogen.

18. A method comprising:

forming a structure comprising polysilicon-comprising material, titanium-comprising material over the polysilicon-comprising material, silicon nitride-comprising material over the titanium-comprising material, and tungsten-comprising material over the silicon nitride-comprising material;

the polysilicon-comprising material consists essentially of polysilicon, the titanium-comprising material consists essentially of elemental titanium, the silicon nitride-comprising material consists essentially of silicon nitride, and the tungsten-comprising material consists essentially of elemental tungsten; and

annealing the structure to cause at least a part of the silicon nitride to be converted into conductive material comprising titanium, silicon and nitrogen.

19. A conductive line construction comprising:

polysilicon-comprising material;

a metal silicide directly against the polysilicon of the polysilicon-comprising material;

elemental tungsten;

TiSi x N y between the elemental tungsten and the metal silicide;

titanium nitride between the TiSi x N y and the metal silicide, the TiSi x N y being directly against the titanium nitride, the titanium nitride being directly against the metal silicide; and

silicon nitride between the TiSi x N y and the elemental tungsten, the silicon nitride being no thicker than 10 Angstroms, the elemental tungsten being directly against the silicon nitride, and the silicon nitride being directly against the TiSi x N y .

Assignments (5)
RELEASE OF SECURITY INTEREST Recorded Nov 15, 2019
From: JPMORGAN CHASE BANK, N.A., AS COLLATERAL AGENT
To: MICRON TECHNOLOGY, INC.
Reel/Frame 051041/0317 →
RELEASE OF SECURITY INTEREST Recorded Oct 14, 2019
From: MORGAN STANLEY SENIOR FUNDING, INC., AS COLLATERAL AGENT
To: MICRON TECHNOLOGY, INC.
Reel/Frame 050724/0392 →
SUPPLEMENT NO. 12 TO PATENT SECURITY AGREEMENT Recorded Apr 19, 2019
From: MICRON TECHNOLOGY, INC.
To: MORGAN STANLEY SENIOR FUNDING, INC., AS COLLATERAL AGENT
Reel/Frame 048948/0677 →
SUPPLEMENT NO. 3 TO PATENT SECURITY AGREEMENT Recorded Apr 19, 2019
From: MICRON TECHNOLOGY, INC.
To: JPMORGAN CHASE BANK, N.A., AS COLLATERAL AGENT
Reel/Frame 048951/0902 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 18, 2019
From: KUSUMOTO, KENICHI; IUCHI, YASUTAKA; SHIMAMURA, AKIE
To: MICRON TECHNOLOGY, INC.
Reel/Frame 048056/0307 →