Method of forming a contact in a semiconductor device utilizing a plasma treatment

• US 6,911,382 B2
• Filed: 11/25/2003
• Issued: 06/28/2005
• Est. Priority Date: 12/30/2002
• Status: Expired due to Fees

• Current Assignee: DONGBU ELECTRONICS CO., LTD. (DB HiTek Co., Ltd.)
• Original Assignee: DONGBU ELECTRONICS CO., LTD. (DB HiTek Co., Ltd.)
• Inventors: Seo, Bo Min, Jung, Byung Hyun
• Primary Examiner(s): Chambliss, Alonzo
• Assistant Examiner(s): Brunson, Monique
• Application Number:
  US10/721,978
• Publication Number:
  US 20040127017A1
• Time in Patent Office: 581 Days
• Field of Search: 438/530, 438/533, 438/627, 438/637, 438/639, 438/643, 438/653, 438/667, 438/675, 257/773, 257/774
• US Class Current: 438/533
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners

Abstract

Semiconductor devices and methods to form a contact of a semiconductor device are disclosed. An example method to form a contact includes forming an insulating layer on a substrate; etching the insulating layer to form a contact hole; depositing a silicon layer on sidewalls and an undersurface of the contact hole; forming a silicon spacer on the sidewalls of the contact hole by etching the silicon layer; transforming the silicon spacer to a silicon nitride spacer; depositing a diffusion barrier on the silicon nitride spacer; and filling the contact hole with tungsten. Because the silicon nitride spacer formed on the sidewalls of the contact hole can serve as a leakage current blocking layer, the yield and the reliability of the semiconductor devices manufactured by this example process are enhanced.

Claims

1. A method to form a contact comprising:

forming an insulating layer on a substrate;

etching the insulating layer to form a contact hole;

depositing a silicon layer on sidewalls and an undersurface of the contact hole;

forming a silicon spacer on the sidewalls of the contact hole by etching the silicon layer;

plasma treating the silicon spacer to form a silicon nitride spacer;

depositing a diffusion barrier on the silicon nitride spacer; and

filling the contact hole with tungsten.

2. A method as defined in claim 1, wherein depositing the silicon layer on the sidewalls and the undersurface of the contact hole comprises depositing the silicon layer on the sidewalls and the undersurface of the contact hole in a furnace at a temperature of approximately 50˜

700°

C. and a pressure of approximately 0.1˜

1 Torr.

3. A method as defined in claim 2, wherein depositing the silicon layer on the sidewalls and then undersurface of the contact hole further comprises injecting approximately 1˜

5 standard liters per minute of SiH₄ gas into the furnace.

4. A method as defined in claim 1, wherein forming the silicon spacer on the sidewalls of the contact hole by etching the silicon layer further comprises anisotropic etching the silicon layer in a chamber of Cl₂ and HBr gases atmosphere.

5. A method as defined in claim 1, wherein forming the silicon spacer on the sidewalls of the contact hole by etching the silicon layer further comprises injecting approximately 10˜

50 sccm of Cl₂ and approximately 100˜

300 sccm of HBr into a chamber.

6. A method as defined in claim 5 wherein the pressure in the chamber is approximately 1˜

50 mTorr.

7. A method as defined in claim 1, wherein plasma treating the silicon spacer to form the silicon nitride spacer comprises NH₃ plasma treating the silicon spacer by increasing a density of the NH₃ plasma in a chamber.

8. A method as defined in claim 1, wherein plasma treating the silicon spacer to form the silicon nitride spacer comprises and NH₃ plasma treatment which adopts an inductive coupled plasma scheme.

9. A method as defined in claim 1, wherein plasma treating the silicon spacer to form the silicon nitride spacer comprises plasma treating the silicon spacer at a pressure of approximately 1˜

100 mTorr and injecting an NH₃ gas atmosphere into a chamber at approximately 10˜

100 sccm.

10. A method as defined in claim 1, wherein the diffusion barrier prevents tungsten from being diffused.

11. A method to form a contact comprising:

forming an insulating layer on a substrate;

etching the insulating layer to form a contact hole;

depositing a silicon layer on sidewalls and an undersurface of the contact hole;

forming a silicon spacer on the sidewalls of the contact hole by etching the silicon layer;

annealing the silicon spacer through a N₂ or NH₃ gas atmosphere heat treatment to form a silicon nitride spacer;

depositing a diffusion barrier on the silicon nitride spacer; and

filling the contact hole with tungsten.

12. A method as defined in claim 11, wherein depositing the silicon layer on the sidewalls and the undersurface of the contact hole comprises depositing the silicon layer in a furnace at a temperature of approximately 500˜

70°

C. and a pressure of approximately 0.1˜

1 Torr.

13. A method as defined in claim 12 wherein depositing the silicon layer comprises injecting SiH₄ gas into the furnace at approximately 1˜

5 slm.

14. A method as defined in claim 11, wherein etching the silicon layer comprises anisotropic etching the silicon layer in a chamber of Cl₂ and HBr gases atmosphere.

15. A method as defined in claim 14, wherein the Cl₂ is injected into the chamber at approximately 10˜

50 sccm and the HBr is injected into the chamber at approximately 100˜

300 sccm, and wherein a pressure of the chamber is approximately 1˜

50 mTorr.

16. A method as defined in claim 11, wherein the N₂ or NH₃ gas is injected into the chamber at approximately 5˜

20 slm and wherein the temperature in the chamber is approximately 600˜

800°

C.

17. A method as defined in claim 11, wherein the diffusion barrier prevents tungsten from being diffused.