Fin-type antifuse

• US 7,691,684 B2
• Filed: 07/31/2008
• Issued: 04/06/2010
• Est. Priority Date: 10/08/2004
• Status: Active Grant

• Current Assignee: Globalfoundries US Incorporated (GlobalFoundries, Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Nowak, Edward J., Breitwisch, Matthew J., Lam, Chung H.
• Primary Examiner(s): Tran; Thien F
• Application Number:
  US12/183,169
• Publication Number:
  US 20080286905A1
• Time in Patent Office: 614 Days
• Field of Search: 438/131, 438/467, 438/600, 438/957, 257/50, 257/530, 257/E21.346, 257/E21.592
• US Class Current: 438/131
• 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 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: H01L 2924/3011 Impedance

Abstract

A method of forming an antifuse forms a material layer and then patterns the material layer into a fin. The center portion of the fin is converted into a substantially non-conductive region and the end portions of the fin into conductors. The process of converting the center portion of the fin into an insulator allows a process of heating the fin above a predetermined temperature to convert the insulator into a conductor. Thus, the fin-type structure that can be selectively converted from an insulator into a permanent conductor using a heating process.

Claims

1. A method of forming an antifuse structure, said method comprising:

forming a material layer;

patterning said material layer into a fin;

converting a center portion of said fin into a substantially non-conductive region; and

converting end portions of said fin into conductors;

wherein said process of converting said center portion of said fin into a substantially non-conductive region allows a subsequent process of heating said fin above a predetermined temperature to convert said substantially non-conductive region into a conductor.

2. The method in claim 1, wherein said process of converting said center portion of said fin into a substantially non-conductive region comprises:

masking ends of said fin such that a center portion of said fin is unprotected; and

implanting ions into said center portion of said fin.

3. The method in claim 1, wherein said process of converting said center portion of said fin into a substantially non-conductive region changes said center portion of said fin into an amorphous material.

4. The method in claim 1, wherein said process of converting said center portion of said fin into a substantially non-conductive region changes said center portion into amorphous silicon and said heating of said fin changes said center portion of said fin into polycrystalline silicon.

5. The method in claim 1, wherein said process of converting said end portions of said fin into conductors comprises:

protecting said center portion of said fin; and

siliciding said end portions of said fin.

6. The method in claim 1, wherein said heating of said fin changes a conductivity level of said center portion of said fin to be approximately 10 times more conductive after being heated above said predetermined temperature when compared to a conductivity level of said center portion before heating.

7. A method of forming an antifuse structure, said method comprising:

forming a material layer;

patterning said material layer into a fin;

converting end portions of said fin into a P-type end and an N-type end;

converting a center portion of said fin into a P-N junction; and

wherein said process of converting said center portion of said fin into said P-N junction allows a subsequent process of heating said fin above a predetermined temperature to permanently change characteristics of said P-N junction.

8. The method in claim 7, wherein said process of converting said center portion into a P-N junction comprises:

masking ends of said fin such that a center portion of said fin is unprotected;

implanting ions into said center portion of said fin; and

after said process of converting said end portions of said fin, heating said fin sufficiently to drive impurities from said ends of said fin into said center of said fin.

9. The method in claim 8, wherein said process of implanting ions into said center portion of said fin changes said center portion of said fin into an amorphous material.

10. The method in claim 7, wherein said process of converting said end portions of said fin into conductors comprises:

protecting said center portion of said fin;

protecting said N-type end and implanting P-type impurities into said P-type end; and

protecting said P-type end and implanting N-type impurities into said N-type end.

11. The method in claim 10, wherein said N-type impurities and said P-type impurities comprise opposite type impurities.

12. The method in claim 7, wherein said heating of said fin changes mid-gap density of states of said center portion of said fin to be approximately 100 times lower than mid-gap density of states of said center portion of said fin before heating.

13. A method of forming an antifuse structure, said method comprising:

forming a material layer;

patterning said material layer into a fin;

converting a center portion of said fin into a substantially non-conductive region; and

converting end portions of said fin into conductors;

wherein said process of converting said center portion of said fin into a substantially non-conductive region allows a subsequent process of heating said fin above a predetermined temperature to convert said substantially non-conductive region into a conductor, and

wherein said process of converting said center portion of said fin into a substantially non-conductive region changes said center portion of said fin into an amorphous material.

14. The method in claim 13, wherein said process of converting said center portion of said fin into a substantially non-conductive region comprises:

masking ends of said fin such that a center portion of said fin is unprotected; and

implanting ions into said center portion of said fin.

15. The method in claim 13, wherein said process of converting said center portion of said fin into a substantially non-conductive region changes said center portion into amorphous silicon and said heating of said fin changes said center portion of said fin into polycrystalline silicon.

16. The method in claim 13, wherein said process of converting said end portions of said fin into conductors comprises:

protecting said center portion of said fin; and

siliciding said end portions of said fin.

17. The method in claim 13, wherein said heating of said fin changes a conductivity level of said center portion of said fin to be approximately 10 times more conductive after being heated above said predetermined temperature when compared to a conductivity level of said center portion before heating.