Antifuse element with electrical or optical programming

• US 5,485,032 A
• Filed: 12/08/1994
• Issued: 01/16/1996
• Est. Priority Date: 12/18/1992
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Schepis, Dominic J., Srikrishnan, Kris V., Subbanna, Seshadri, Tejwani, Manu J.
• Primary Examiner(s): Crane, Sara W.
• Assistant Examiner(s): BOWERS, COURTNEY
• Application Number:
  US08/355,206
• Time in Patent Office: 404 Days
• Field of Search: 257/530, 257/529, 257/765
• US Class Current: 257/530
• CPC Class Codes: H01L 21/76888 By rendering at least a portion of the conductor non conductive, e.g. oxidation
• CPC Class Codes: H01L 21/76894 using a laser, e.g. laser cutting, laser direct writing, laser repair
• CPC Class Codes: H01L 23/5252 comprising anti-fuses, i.e. connections having their state changed from non-conductive to conductive
• CPC Class Codes: H01L 23/5254 the change of state resulting from the use of an external beam, e.g. laser beam or ion beam
• 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: Y10S 438/933 Germanium or silicon or Ge-Si on III-V

Abstract

A programmable antifuse element comprising adjacent bodies of germanium and aluminum or aluminum allow form a low resistance connection of good mechanical and thermal properties when heated to a temperature where alloying of the aluminum and germanium occurs. Heating for the purpose of programming the antifuse element can be done by electrical resistance heating in the-germanium, which may be doped to achieve a desired resistance value, or by laser irradiation. Due to the high resistance of intrinsic or lightly doped germanium, a resistance change ratio of greater than 10,000:1 is achieved.

Claims

1. An integrated circuit including

at least two conductors, and

a programmable connector means for selectively alloying aluminum with germanium extending between said at least two conductors, said programmable connector means including

a body of germanium adjacent a body containing aluminum and forming a source of aluminum for alloying with said body of germanium.

8. An integrated circuit as recited in claim 1, wherein said body of germanium is lightly doped.

9. An integrated circuit as recited in claim 1, wherein said body of germanium is formed as a stud by deposition in a via in an insulative layer.

10. An integrated circuit as recited in claim 9, further including a layer of tungsten deposited in said via.

11. An integrated circuit as recited in claim 9, further including a layer of aluminum deposited in said via.

12. An integrated circuit as recited in claim 1, wherein said body containing aluminum is a connector.

2. An antifuse element comprising

at least two conductors, and

a programmable means for selectively alloying aluminum with germanium extending between said at least two conductors, said programmable means including

at least one body containing aluminum and a body containing germanium adjacent said at least one body of aluminum, at least one said body containing aluminum forming a source of aluminum for alloying with said body of germanium.

3. An antifuse element as recited in claim 2, wherein said body of germanium is lightly doped.

4. An antifuse element as recited in claim 2, wherein said body of germanium is formed as a stud by deposition in a via in an insulative layer.

5. An antifuse element as recited in claim 4, further including a layer of tungsten deposited in said via.

6. An antifuse element as recited in claim 4, further including a layer of aluminum deposited in said via.

7. An antifuse element as recited in claim 2, wherein said at least one body containing aluminum is a connector.

13. An antifuse element comprising

at least two conductors,

a programmable connector means for selectively alloying aluminum with germanium in a via extending between said at least two conductors, said programmable connector means including

a body of germanium adjacent a body containing aluminum and forming a source of aluminum for alloying with said body of germanium.

14. An antifuse element as recited in claim 13, wherein said body of germanium is lightly doped.

15. An antifuse element as recited in claim 13, wherein said body of germanium is formed as a stud by deposition in said via in an insulative layer.

16. An antifuse element as recited in claim 15, further including a layer of tungsten deposited in said via.

17. An antifuse element as recited in claim 15, further including a layer of aluminum deposited in said via.

18. An antifuse element as recited in claim 13, wherein said body containing aluminum is a connector.