Multilayered intermetallic connection for semiconductor devices

• US 5,071,714 A
• Filed: 04/17/1989
• Issued: 12/10/1991
• Est. Priority Date: 04/17/1989
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: White, James F., Rodbell, Kenneth P., Totta, Paul A.
• Primary Examiner(s): Zimmerman, John J.
• Application Number:
  US07/339,533
• Time in Patent Office: 967 Days
• Field of Search: 428/651, 428/660, 428/661, 428/620, 428/610, 357/71, 204/192.15, 204/192.17
• US Class Current: 428/620
• CPC Class Codes: H01L 21/4846 Leads on or in insulating or insulated substrates, e.g. metallisation H01L21/4821 takes precedence; metallisation of ceramics in general C04B41/51; printed circuits H05K3/00
• CPC Class Codes: H01L 23/49866 characterised by the materials materials of the substrates H01L23/14, of the lead-frames H01L23/49579
• 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
• CPC Class Codes: H05K 1/09 Use of materials for the conductive, e.g. metallic pattern
• CPC Class Codes: H05K 3/16 by cathodic sputtering
• CPC Class Codes: H05K 3/388 by the use of a metallic or inorganic thin film adhesion layer
• CPC Class Codes: Y10T 428/12528 Semiconductor component
• CPC Class Codes: Y10T 428/12743 Next to refractory [Group IVB, VB, or VIB] metal-base component

Abstract

A sputtered low copper concentration multilayered, device interconnect metallurgy structure is disclosed herein. The interconnect metallization structure comprises a sputtered aluminum-copper (<2) weight percent copper conductor. In the preferred embodiment, the AlCu conductor has formed on one or both of its surfaces a layer of an intermetallic compound formed from a Group IVA metal and aluminum. The Group IVA metal is deposited by sputtering. Optionally, onto said top intermetallic layer is further deposited a non-reflective, non-corrosive, etch-stop, capping layer.

Claims

1. A metallization structure for the interconnection of semiconductor devices on a substrate comprising:

a) a layer of sputter deposited aluminum-copper of greater than 0.0% and less than 2.0% copper by weight; and

b) an intermetallic layer formed at the surface of said aluminum-copper layer, said intermetallic formed of a sputter-deposited Group IVA metal and aluminum of said aluminum-copper layer.

2. A metallization structure according to claim 1 wherein said structure comprises:

a) a first intermetallic layer;

b) a layer of sputter deposited aluminum-copper containing greater than 0.0% and less than 2.0% copper by weight;

c) a second intermetallic layer similar to (a) above deposited on layer (b) above; and

d) a metal overlayer deposited on layer (c).

3. A metallization structure according to claim 2 wherein said metal overlayer is selected from the group comprising aluminum, aluminum-compounds or titanium-compounds.

4. A metallization structure according to claim 2 wherein said metal overlayer is aluminum-copper alloy containing greater than 0.0% to less than 2.0% copper by weight.

5. A metallization structure according to claim 2 wherein said intermetallic layer is approximately 700 Å

thick.

6. A metallization structure according to claim 2 wherein said aluminum-copper layer is approximately 8,500 Å

thick.

7. A metallization structure according to claim 2 wherein said metal overlayer is 100 Å

-500 Å

thick.

8. A metallization structure according to claim 2 wherein one metal of said intermetallic layer is selected from the group comprising the Group IVA metals of the Periodic Table.

9. A metallization structure according to claim 1 wherein said structure comprises:

a) a first layer of sputter-deposited aluminum-copper containing greater than 0.0% and less than 2.0% copper by weight;

b) an intermetallic layer deposited on layer (a) above;

c) a second layer of the metallurgy of (a) above deposited on (b).

10. A metallization structure according to claim 9 wherein one metal of said intermetallic layer is selected from the group comprising the Group IVA metals of the Periodic Table.

11. A metallization structure according to claim 9 wherein the intermetallic layer is approximately 1500 Å

thick.

12. A metallization structure according to claim 11 wherein the aluminum-copper layers are approximately 4,250 Å

thick.

13. A metallization structure according to claim 1 wherein said structure comprises:

a) a first layer of sputter deposited aluminum-copper containing 0.5% copper by weight approximately 4,250 Å

thick,

b) a layer of TiAl₃ deposited on layer (a) above and approximately 1500 Å

thick, and

c) a second layer of the metallurgy of (a) above deposited on (b).

14. A metallization structure according to claim 1 wherein said structure comprises:

a) a first layer of TiAl₃ approximately 700 Å

thick,

b) a layer of sputter deposited aluminum copper containing 0.5% copper by weight deposited onto said TiAl₃ and being approximately 8,500 Å

thick,

c) a second layer of the metallurgy of (a) above deposited onto said layer onto (b) above, and

d) a layer of sputter deposited aluminum copper containing 0.5% copper by weight deposited on layer (c) above and being approximately 250 Å

thick.

15. A method of forming a structure for connecting semiconductor devices on a substrate comprising the steps of:

a) sputter depositing a first layer of at least one of the Group IVA metals onto said substrate,

b) sputter depositing onto said layer of the Group IVA metals a layer of aluminum copper of greater than 0.0% and less than 2.0% copper by weight,

c) sputter depositing a second layer of the same Group IVA metal as in step a, and

d) annealing the structure to form an intermetallic of the Group IVA metals and aluminum.

16. A method according to claim 15 wherein said annealed interconnect structure is patterned to connect the devices.