Re-settable tristate programmable device

• US 6,472,230 B2
• Filed: 03/20/2002
• Issued: 10/29/2002
• Est. Priority Date: 10/13/1999
• Status: Expired due to Term

• Current Assignee: GlobalFoundries, Inc.
• Original Assignee: International Business Machines Corporation
• Inventors: Williams, Richard Q., Motsiff, William T., Chediak, J. Alex, Pricer, Wilbur D., Kimmel, Kurt R.
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Wille, Douglas A.
• Application Number:
  US10/102,381
• Publication Number:
  US 20020096735A1
• Time in Patent Office: 223 Days
• Field of Search: 257/529, 257/530, 438/3, 438/4, 438/6, 438/14
• US Class Current: 438/3
• CPC Class Codes: G11C 11/5607 using magnetic storage elements
• CPC Class Codes: G11C 2216/26 Floating gate memory which is adapted to be one-time programmable [OTP], e.g. containing multiple OTP blocks permitting limited update ability
• CPC Class Codes: H01L 23/5258 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

Abstract

A method and structure for a programmable circuit that includes a magnetic device having a reluctance which is alterable.

Claims

1. A method of programming magnetic devices comprising:

aligning magnetic fields of said magnetic devices in a first direction;

selectively aligning magnetic fields of first devices of said magnetic devices in a second direction; and

optionally sensing a magnetic state of said magnetic devices.

2. The method in claim 1, wherein said aligning comprises heating and cooling said magnetic devices in a first magnetic field and said selectively aligning comprises heating and cooling said first devices in a second magnetic field.

3. The method in claim 2, wherein said second magnetic field has a directional characteristic different that said first magnetic field.

4. The method in claim 2, wherein said second magnetic field has a strength less than that of said first magnetic field.

5. The method in claim 2, wherein said heating comprises selective application of laser energy.

6. The method in claim 1, further comprising selectively neutralizing magnetic fields of second devices of said magnetic devices.

7. The method in claim 6, wherein said neutralizing comprises heating and cooling said second magnetic devices in a magnetic field equal to and opposite the Earth'"'"'s magnetic field.

8. The method in claim 6, wherein said neutralizing comprises removing said second devices.

9. A method of programming fuses comprising:

aligning magnetic fields of said fuses in a first direction;

selectively aligning magnetic fields of first fuses of said fuses in a second direction; and

sensing a magnetic state of said fuses.

10. The method in claim 9, wherein said aligning comprises heating and cooling said fuses in a first magnetic field and said selectively aligning comprises heating and cooling said first fuses in a second magnetic field.

11. The method in claim 10, wherein said second magnetic field has a directional characteristic different that said first magnetic field.

12. The method in claim 10, wherein said second magnetic field has a strength less than that of said first magnetic field.

13. The method in claim 10, wherein said heating comprises selective application of laser energy.

14. The method in claim 9, further comprising selectively neutralizing magnetic fields of second fuses of said fuses.

15. The method in claim 14, wherein said neutralizing comprises heating and cooling said second fuses in a magnetic field equal to and opposite the Earth'"'"'s magnetic field.

16. The method in claim 14, wherein said neutralizing comprises removing said second fuses.