Method of fabricating metal line structure

• US 5,795,796 A
• Filed: 04/18/1996
• Issued: 08/18/1998
• Est. Priority Date: 12/26/1995
• Status: Expired due to Term

• Current Assignee: LG Semico Company Limited (SK Hynix Inc.)
• Original Assignee: LG Semico Company Limited (SK Hynix Inc.)
• Inventors: Kim, Do Heyoung
• Primary Examiner(s): Niebling, John
• Assistant Examiner(s): BILODEAU, THOMA
• Application Number:
  US08/634,531
• Time in Patent Office: 852 Days
• Field of Search: 437/189, 437/190, 437/192, 437/195, 437/247, 437/194
• US Class Current: 438/660
• CPC Class Codes: H01L 21/76831 in via holes or trenches, e.g. non-conductive sidewall liners
• CPC Class Codes: H01L 21/76834 formation of thin insulating films on the sidewalls or on top of conductors H01L21/76831 takes precedence
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76856 by treatment in plasmas or gaseous environments, e.g. nitriding a refractory metal liner
• CPC Class Codes: H01L 23/53223 Additional layers associated with aluminium layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 23/53233 Copper alloys
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• 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

A method of fabricating a metal line includes the steps of preparing a semiconductor substrate, depositing a first metal on the semiconductor substrate, heat-treating the first metal to form a first metal nitride layer, depositing a second metal on the first metal nitride layer, heat treating the second metal, depositing a third metal on the second metal, and heat treating both the third metal and the second metal to form a metal insulating layer in which the second and the third metals are mixed. The method of fabricating increases the area occupied by the metal line in a contact hole, decreases contact resistance, and increases the speed of the device.

Claims

1. A method of fabricating a metal line comprising the steps of:

preparing a semiconductor substrate;

depositing a first metal on the semiconductor substrate;

heat-treating the first metal to form a first metal nitride layer;

depositing a second metal on the first metal nitride layer;

heat treating the second metal;

depositing a third metal on the second metal; and

heat treating both the third metal and the second metal to form a metal insulating layer in which the second and the third metals are mixed.

2. The method of fabricating the metal line as claimed in claim 1, wherein the first metal is deposited through CVD.

3. The method of fabricating the metal line as claimed in claim 1, wherein the first metal includes either Ti, W, TiSi Or TaSi.

4. The method of fabricating the metal line as claimed in claim 1, wherein the first heat treatment is carried out under the ambient of nitrogen.

5. The method of fabricating the metal line as claimed in claim 1, wherein the first metal nitride layer includes either TiN_x, TaN_x, WN_x, TiSiN_x, or TaSiN_x (0.25<

x<

0.75).

6. The method of fabricating the metal line as claimed in claim 1, wherein the first metal nitride layer is formed to a thickness of about 10 to 500 Å

.

7. The method of fabricating the metal line as claimed in claim 1, wherein the second metal is deposited through CVD.

8. The method of fabricating the metal line as claimed in claim 1, wherein the second heat treatment is carried out under an ambient of oxygen or air.

9. The method of fabricating the metal line as claimed in claim 1, wherein the third metal is deposited through CVD.

10. The method of fabricating the metal line as claimed in claim 1, wherein the third metal is Al, Ti, Zr, Ta or Pd.

11. The method of fabricating the metal line as claimed in claim 1, wherein the third heat treatment is carried out under the ambient of either O₂, N₂, O₂ /N₂, or air.

12. The method of fabricating the metal line as claimed in claim 1, wherein the metal insulating layer mixed with the second and third metal includes Cu, a metal "M", and O.

13. The method of fabricating the metal line as claimed in claim 1, wherein the metal insulating layer mixed with the second and third metal includes Cu, a metal "M", O, and N.

14. The method of fabricating the metal line as claimed in claim 12, wherein the metal "M" is Al, Ti, Zr, Ta or Pd.

15. The method of fabricating the metal line as claimed in claim 13, wherein the metal "M" is Al, Ti, Zr, Ta or Pd.

16. The method of fabricating the metal line as claimed in claim 1, wherein the metal insulating layer mixed with the second and third metal is formed to a thickness of about 10 to 500 Å

.

17. The method of fabricating the metal line as claimed in claim 1, wherein the metal insulating layer has conductivity.

18. The method of fabricating the metal line as claimed in claim 1, wherein the metal nitride layer and the metal insulating layer are used as a barrier.