Simultaneous multiple antifuse programming method

• US 5,371,414 A
• Filed: 05/26/1993
• Issued: 12/06/1994
• Est. Priority Date: 05/26/1993
• Status: Expired due to Term

• Current Assignee: Actel Corporation (Microchip Technology Incorporated)
• Original Assignee: Actel Corporation (Microchip Technology Incorporated)
• Inventors: Galbraith, Douglas C.
• Primary Examiner(s): Westin, Edward P.
• Assistant Examiner(s): DRISCOLL, BENJAMIN
• Application Number:
  US08/067,381
• Time in Patent Office: 559 Days
• Field of Search: 307/202.1, 307/465, 437/170, 437/922, 365/96
• US Class Current: 327/525
• CPC Class Codes: G11C 17/18 Auxiliary circuits, e.g. for writing into memory
• 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

Abstract

A method for simultaneously programming a plurality of antifuses each having a first electrode connected to a common node and each having a second electrode connected to an isolated node electrically isolated from the nodes of each of the other antifuses includes the steps of precharging the common node and the isolated nodes to an intermediate voltage potential selected to minimize the stress on all antifuses; precharging the isolated nodes of selected ones of the antifuses to a first programming voltage potential placing a second programming voltage potential on said common node, the first and second programming voltage potentials selected such that the difference between them is sufficient to cause programming of said antifuses and such that said intermediate potential is substantially centered between them, waiting a predetermined amount of time; and measuring the current flowing between the common node isolated nodes. If the measured current indicates that the desired antifuse has not been programmed the programming process may be attempted a preselected number of times. After the selected antifuses have been programmed, they are individually soaked by passing a soaking current through them.

Claims

1. A method for programming a plurality of antifuses disposed at intersections between a common conductor and a plurality of individual crossing conductors, including the steps of:

dynamically precharging each one of the individual crossing conductors associated with antifuses not to be programmed to a voltage level equal to approximately half of a programming potential difference;

dynamically precharging each one of the individual crossing conductors associated with antifuses to be programmed to one potential of said programming potential difference; and

placing a second potential of said programming potential difference to said common conductor for a time selected to be sufficient to program properly functioning antifuses.

2. The method of claim 1, further including the steps of:

reducing said second potential to a value selected to avoid stressing unprogrammed ones of said antifuses after said time has elapsed;

comparing the current passing through each antifuse to be programmed with magnitude of a current exhibited by a programmed antifuse; and

repeating the steps of claim 1 only if the current passing through any one of said antifuses to be programmed is less than said magnitude of a current exhibited by a programmed antifuse.

3. The method of claim 1, further including the step of passing a soaking current through each one of said antifuses which has been programmed.

4. A method for programming a plurality of antifuses configured to program at a programming voltage potential, said antifuses disposed at intersections between a common conductor and a plurality of individual crossing conductors, including the steps of:

dynamically precharging each one of the individual crossing conductors associated with antifuses not to be programmed to a selected voltage level halfway between a first voltage potential and a second voltage potential, the difference between said first and second voltage potentials comprising said programming voltage potential;

dynamically precharging each one of the individual crossing conductors associated with antifuses to be programmed to said first voltage potential; and

placing said second voltage potential on said common conductor for a time selected to be sufficient to program properly functioning antifuses.

5. The method of claim 4, further including the steps of;

reducing the voltage on said common conductor to said selected voltage potential after said time has elapsed;

comparing the current passing through each antifuse to be programmed with the magnitude of a current exhibited by a programmed antifuse; and

repeating the steps of claim 4 only if the current passing through any one of said antifuses to be programmed is less than said magnitude of a current exhibited by a programmed antifuse.

6. The method of claim 4, further including the step of passing a soaking current through each one of said antifuses which has been programmed.

7. A method for programming a plurality of antifuses associated with a plurality of common conductors, individual ones of said disposed at intersections between one of said common conductors and a plurality of individual crossing conductors intersecting said one of said common conductors, including the steps of:

(1) selecting one of said common conductors;

(2) dynamically precharging each one of the individual crossing conductors associated with antifuses not to be programmed to connect said individual crossing conductors to said selected common conductor to a voltage level halfway between a first voltage potential and a second voltage potential, the difference between said first and second voltage potentials comprising said programming voltage potential;

(3) dynamically precharging each one of the individual crossing conductors associated with antifuses to be programmed to said first voltage potential;

(4) placing said second voltage potential to said common conductor for a time selected to be sufficient to program property functioning antifuses; and

(5) repeating steps (1)-(4) for each one of said common conductors.

8. The method of claim 7, further including for each performance of steps (1)-(4) therein performance of the further steps of:

reducing said second voltage potential to a value selected to avoid stressing unprogrammed ones of said antifuses after said time has elapsed;

comparing the current passing through each antifuse to be programmed with the magnitude of a current exhibited by a programmed antifuse; and

repeating the steps of claim 7 only if the current passing through any one of said antifuses to be programmed is less than said magnitude of a current exhibited by a programmed antifuse.

9. The method of claim 7, further including the step of passing a soaking current through each one of said antifuses which has been programmed.

10. A method for programming a plurality of antifuses associated with a plurality of common conductors, said antifuses configured to program at a programming voltage potential, individual ones of said antifuses disposed at intersections between one of said common conductors and a plurality of individual crossing conductors intersecting said one of said common conductors, including the steps of:

(1) selecting one said common conductors;

(2) dynamically precharging each one of the individual crossing conductors associated with antifuses not to be programmed to connect said individual crossing conductors to said selected common conductor to a selected voltage level halfway between a first voltage potential and a second voltage potential, the difference between said first and second voltage potentials comprising said programming voltage potential;

(3) dynamically precharging each one of the individual crossing conductors associated with antifuses to be programmed to said first voltage potential;

(4) placing said second voltage potential on said common conductor for a time selected to be sufficient to program properly functioning antifuses; and

(5) repeating steps (1)-(4) for each one of said common conductors.

11. The method of claim 10, further including for each performance of steps (1)-(4) therein performance of the further steps of;

reducing said second potential to approximately said selected voltage potential after said time has elapsed;

comparing the current passing through each antifuse to be programmed with the magnitude of a current exhibited by a programmed antifuse; and

repeating the steps of claim 10 only if the current passing through any one of said antifuses to be programmed is less than said magnitude of a current exhibited by a programmed antifuse.

12. The method of claim 10, further including the step of passing a soaking current through each one of said antifuses which has been programmed.