Soft error rate (SER) reduction in advanced silicon processes

• US 8,633,109 B2
• Filed: 02/22/2011
• Issued: 01/21/2014
• Est. Priority Date: 08/04/2010
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Lee, Yung-Huei, Tsai, Chou-Jie, Wu, Chia-Fang, Chu, Wei-Cheng, Lee, Jang Jung, Gui, Dong
• Primary Examiner(s): Swanson, Walter H
• Assistant Examiner(s): JEAN BAPTISTE, WILNER
• Application Number:
  US13/031,897
• Publication Number:
  US 20120032334A1
• Time in Patent Office: 1,064 Days
• Field of Search: 257/770, 430/315, 438/675, 438/685, 438/597
• US Class Current: 438/675
• CPC Class Codes: C23C 16/0272 Deposition of sub-layers, e.g. to promote the adhesion of the main coating
• CPC Class Codes: C23C 16/045 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 16/14 Deposition of only one other metal element
• CPC Class Codes: C23C 16/4402 Reduction of impurities in the source gas
• CPC Class Codes: H01L 21/28506 of conductive layers
• CPC Class Codes: H01L 21/28562 Selective deposition
• CPC Class Codes: H01L 21/76876 for deposition from the gas phase, e.g. CVD
• CPC Class Codes: H01L 23/485 consisting of layered constructions comprising conductive layers and insulating layers, e.g. planar contacts H01L23/4821, H01L23/4822, H01L23/4824, H01L23/4825 take precedence; materials H01L23/532, bond pads H01L24/02, bump connectors H01L24/10
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

Provided is a method of fabricating a semiconductor device. The method includes providing a substrate. The method includes forming a portion of an interconnect structure over the substrate. The portion of the interconnect structure has an opening. The method includes obtaining a boron-containing gas that is free of a boron-10 isotope. The method includes filling the opening with a conductive material to form a contact. The filling of the opening is carried out using the boron-containing gas. Also provided is a semiconductor device. The semiconductor device includes a substrate. The semiconductor device includes an interconnect structure formed over the substrate. The semiconductor device includes a conductive contact formed in the interconnect structure. The conductive contact has a material composition that includes Tungsten and Boron, wherein the Boron is a ¹¹B-enriched Boron.

Claims

1. A method, comprising:

providing a substrate;

forming a transistor at least partially in the substrate, the transistor having a channel region;

forming a contact hole over the substrate; and

forming a conductive contact in the contact hole using a ¹¹B-enriched Boron material, wherein the forming the conductive contact includes;

forming a Tungsten-containing seed layer in the contact hole through an atomic layer deposition (ALD) process, wherein the ¹¹B-enriched Boron material is used as a precursor in the ALD process; and

performing a chemical vapor deposition (CVD) process after the ALD process, the CVD process forming a Tungsten material on the Tungsten-containing seed layer; and

wherein the forming the conductive contact is carried out in a manner so that the conductive contact is spaced apart from the channel region by less than about 0.5 microns.

2. The method of claim 1, wherein the ¹¹B-enriched Boron material has a ¹¹B content that is higher than a ¹¹B content of a Boron material in nature.

3. The method of claim 1, wherein the ¹¹B-enriched Boron material has a ¹¹B content that is higher than about 95%.

4. The method of claim 1, wherein the forming the conductive contact is carried out in a manner so that the conductive contact includes Tungsten.

5. The method of claim 1, wherein the forming the conductive contact includes forming the Tungsten-containing seed layer using the ¹¹B-enriched Boron material.

6. The method of claim 1, wherein the method is performed as part of a fabrication process belonging to a technology node below a 90-nanometer technology node.

7. The method of claim 1, wherein the ALD process includes a plurality of process cycles, each process cycle including a soaking process followed by a nucleation process.

8. The method of claim 7, wherein:

the soaking process produces the ¹¹B-enriched Boron material from a ¹¹B₂H₆ material; and

the nucleation process produces a layer of Tungsten material from the ¹¹B₂H₆ material and a WF₆ material.

9. The method of claim 8, wherein:

the soaking process includes the following chemical process;

¹¹B₂H₆ =>

2* ¹¹B+3*H₂; and

the nucleation process includes the following chemical process;

WF₆ +¹¹B₂H₆ =>

W+3* ¹¹BF₃ +3*H₂.

10. The method of claim 1, wherein the ¹¹B-enriched Boron material has a ¹¹B content that is higher than about 99.7%.

11. A method, comprising:

providing a substrate;

forming a transistor at least partially in the substrate;

forming a portion of an interconnect structure over the substrate, the portion of the interconnect structure having an opening;

obtaining a Boron-containing gas that is substantially free of a ¹⁰B isotope; and

filling the opening with a conductive material to form a contact, the filling the opening being carried out using the Boron-containing gas, wherein the filling the opening includes;

forming a seed layer in the opening using an atomic layer deposition (ALD) process, the Boron-containing gas being used as a precursor in the ALD process; and

forming a Tungsten material on the seed layer using a chemical vapor deposition (CVD) process; and

wherein the conductive contact is formed to be less than about 0.5 microns from a channel region of the transistor.

12. The method of claim 11, wherein the Boron-containing gas contains a ¹¹B isotope, and wherein a concentration of the ¹¹B isotope in a Boron is greater than about 99.7%, and wherein a concentration of the ¹⁰B isotope in the Boron is less than about 0.3%.

13. The method of claim 12, wherein the ALD process includes a plurality of process cycles, each process cycle including a soaking process followed by a nucleation process.

14. The method of claim 13, wherein:

the soaking process produces the ¹¹B isotope from a ¹¹B₂H₆ material; and

the nucleation process produces a layer of Tungsten material from the ¹¹B₂H₆ material and a WF₆ material.

15. The method of claim 14, wherein:

the soaking process includes the following chemical process;

¹¹B₂H₆ =>

2* ¹¹B+3*H₂; and

the nucleation process includes the following chemical process;

WF₆+¹¹B₂H₆=>

W+3* ¹¹BF₃+3*H₂.

16. The method of claim 11, wherein the filling the opening is carried out in a manner so that the contact is a Tungsten plug.

17. A method, comprising:

synthesizing a ¹¹B-enriched Boron material through a plurality of chemical processes;

fabricating a transistor in a substrate, the transistor belonging to a technology node less than a 90 nanometer technology node, the transistor including a source, a drain, and a channel region disposed between the source and the drain;

forming a dielectric layer over the substrate;

forming an opening in the dielectric layer, the opening exposing one of the source and the drain and being disposed less than about 0.5 microns from the channel region; and

forming a Tungsten plug in the opening, wherein the forming the Tungsten plug includes;

forming a seed layer in the opening through an atomic layer deposition (ALD) process, wherein the ¹¹B-enriched Boron material serves as a precursor in the ALD process, and wherein the ALD process includes a plurality of process cycles, each process cycle including a soaking process followed by a nucleation process; and

performing a chemical vapor deposition (CVD) process after the ALD process, the CVD process depositing a Tungsten material on the seed layer.

18. The method of claim 17, wherein:

the soaking process produces the ¹¹B-enriched Boron material from a ¹¹B₂H₆ material; and

the nucleation process produces a layer of Tungsten material from the ¹¹B₂H₆ material and a WF₆ material.

19. The method of claim 18, wherein:

the soaking process includes the following chemical process;

¹¹B₂H₆=>

2* ¹¹B+3*H₂; and

the nucleation process includes the following chemical process;

WF₆+¹¹B₂H₆=>

W+3* ¹¹BF₃+3*H₂.

20. The method of claim 17, wherein the synthesizing the ¹¹B-enriched Boron material is performed such that a concentration of a ¹¹B isotope in the ¹¹B-enriched Boron material is greater than about 99.7%.