Transistors, Semiconductor Devices, and electronic devices including transistor gates with conductive elements including cobalt silicide

• US 20140159172A1
• Filed: 02/18/2014
• Published: 06/12/2014
• Est. Priority Date: 12/08/2006
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Hu, Yongjun Jeff
• Granted Patent: US 9,882,015 B2
• Time in Patent Office: Days
• US Class Current: 257/413
• CPC Class Codes: H01L 27/105 including field-effect components
• CPC Class Codes: H01L 29/40114 the electrodes comprising a conductor-insulator-conductor-insulator-semiconductor structure
• CPC Class Codes: H01L 29/4975 being a silicide layer, e.g. TiSi2
• CPC Class Codes: H10B 12/30 DRAM devices comprising one-transistor - one-capacitor [1T-1C] memory cells
• CPC Class Codes: H10B 12/488 Word lines
• CPC Class Codes: H10B 41/30 characterised by the memory core region
• CPC Class Codes: H10B 69/00 Erasable-and-programmable ROM [EPROM] devices not provided for in groups H10B41/00 - H10B63/00, e.g. ultraviolet erasable-and-programmable ROM [UVEPROM] devices

Abstract

A method for fabricating a transistor gate with a conductive element that includes cobalt silicide includes use of a sacrificial material as a place-holder between sidewall spacers of the transistor gate until after high temperature processes, such as the fabrication of raised source and drain regions, have been completed. In addition, semiconductor devices (e.g., DRAM devices and NAND flash memory devices) with transistor gates that include cobalt silicide in their conductive elements are also disclosed, as are transistors with raised source and drain regions and cobalt silicide in the transistor gates thereof. Intermediate semiconductor device structures that include transistor gates with sacrificial material or a gap between upper portions of sidewall spacers are also disclosed.

Claims

1. A semiconductor device comprising:

at least one transistor with a transistor gate comprising a conductive element including cobalt silicide; and

source and drain regions proximate to the transistor gate, the source and drain regions spaced from silicide material including the cobalt silicide.

3. The semiconductor device of claim 1, wherein the conductive element further comprises tantalum silicide beneath the cobalt silicide.

4. The semiconductor device of claim 3, wherein the tantalum silicide has a thickness of about 200 Å

to about 300 Å

.

5. The semiconductor device of claim 3, wherein the cobalt silicide has a thickness of about 300 Å

to about 600 Å

.

6. The semiconductor device of claim 3, wherein the conductive element further comprises conductively doped polysilicon beneath the tantalum silicide.

2. (canceled)

7. (canceled)

8. (canceled)

9. A transistor, comprising:

a transistor gate comprising;

a conductive element comprising cobalt silicide; and

sidewall spacers adjacent to lateral edges of the conductive element;

a source region located adjacent to a first side of the transistor gate,

the source region isolated from all cobalt including the cobalt silicide of the conductive element; and

a drain region located adjacent to a second side of the transistor gate, the drain region isolated from all cobalt including the cobalt silicide of the conductive element.

10. The transistor of claim 9, wherein the transistor gate further comprises tantalum silicide adjacent the cobalt silicide.

11. The transistor of claim 10, wherein the transistor gate further comprises conductively doped polysilicon adjacent the tantalum silicide.

19. The transistor of claim 9, wherein the transistor gate further comprises a gate oxide underlying the conductive element.

20. The transistor of claim 19, wherein the gate oxide extends directly between the source region and the drain region.

12. An electronic device, comprising at least one semiconductor device including at least one transistor with a transistor gate comprising a conductive element including cobalt silicide, all silicide of the at least one transistor contained in the transistor gate.

21. The electronic device of claim 12, wherein the at least one semiconductor device comprises dynamic random access memory comprising the at least one transistor.

22. The electronic device of claim 12, wherein the at least one semiconductor device comprises a NAND flash memory device comprising the at least one transistor.

23. The electronic device of claim 12, wherein the conductive element further comprises tantalum silicide.

13. A semiconductor device comprising at least one transistor comprising:

a transistor gate comprising;

a conductive element comprising cobalt silicide; and

a gate oxide on a surface of a substrate on which the transistor gate is disposed;

source and drain regions on opposite sides of the transistor gate, the source and drain

regions physically isolated from all silicide material including the cobalt silicide of the conductive element; and

a dielectric material directly on the source and drain regions.

14. The semiconductor device of claim 13, wherein the conductive element of the transistor gate further comprises tantalum silicide beneath the cobalt silicide.

15. The semiconductor device of claim 14, wherein the conductive element further comprises polysilicon beneath the tantalum silicide.

16. The semiconductor device of claim 13, wherein the dielectric material comprises at least one of doped silicon dioxide, borophosphosilicate glass, phosphosilicate glass, and borosilicate glass.

17. The semiconductor device of claim 13, wherein the conductive element is recessed relative to an upper surface of the dielectric material.

18. The semiconductor device of claim 13, wherein the transistor gate further comprises a transistor gate cap over the conductive element.