Method and apparatus for programming anti-fuse devices

A method of assembling pluralities of circuit elements, anti-fuse devices, transistors, and supply buses, and a control bus network for forming a programmable array logic device on a substrate and for injecting voltages and sensing voltages at nodes between adjacent anti-fuse device comprising:

• locating the circuit elements at selected locations on the substrate;
• interposing one or more anti-fuse devices in series between each one circuit element that is connectable to each other circuit element located on the substrate;
• passing a pair of supply buses adjacent each antifuse device so that the same pair of supply buses are adjacent each anti-fuse device connected in a series string of anti-fuse devices;
• connecting each anti-fuse device to its adjacent pair of supply buses by a first transistor connected between one end of the anti-fuse device and one of the pair of supply buses and a second transistor connected between the other end of the anti-fuse device and the other of the pair of supply buses;
• providing a voltage driver for each control bus for applying a selected voltage on said supply bus;
• providing a voltage detector at each of the plurality of supply buses for observing the voltage on the supply bus;
• and
• connecting each of the transistors to the control bus network and configuring the control bus network so that each transistor connected between an anti-fuse node and a supply bus can be turned ON for passing the voltage at the node along the supply bus to the voltage monitor for the supply bus and for injecting a voltage applied to the supply bus into the node, and so that each first and second transistors connecting one anti-fuse between a pair of supply buses can be turned ON for applying the selected voltages respectively applied to the pair of supply buses to the one anti-fuse device.

A circuit for programming an anti-fuse device comprising:

• a first anti-fuse device having a first end and a second end and a threshold programming voltage;
• a first transistor and a second transistor respectively connected to the first and second ends of the first anti-fuse device in series, each transistor having an ON and OFF condition;
• a first voltage supply bus for receiving a first voltage and a second voltage supply bus for receiving a second voltage, wherein the first transistor, first antifuse device and second transistor form a series connection between the first voltage supply bus and the second supply bus;
• and
• a control bus network connected to the first and second transistors for turning ON and OFF the first and second transistors.

A circuit for programming an anti-fuse device comprising:

• a first anti-fuse device and a second anti-fuse device, each anti-fuse device having a first end and a second end and a threshold programming voltage, the first and second anti-fuse devices being connected in series at the second end of the first anti-fuse device;
• a first voltage supply bus and a second voltage supply bus;
• a first programming transistor connected between the first voltage supply bus and the first end of the first anti-fuse device;
• a second programming transistor connected between the second voltage supply bus and the second end of the first anti-fuse;
• a third programming transistor connected between the first voltage supply bus and the first end of the second anti-fuse;
• a fourth programming transistor connected between the second voltage supply bus and the second end of the second anti-fuse;
• and
• a control bus network for turning the first, second, third and fourth programming transistors ON and OFF to program selectively one of the first and second anti-fuse devices.

A circuit for programming an anti-fuse device comprising:

• a first anti-fuse device and a second anti-fuse device each anti-fuse device having a first end and a second end and a threshold programming voltage, the first and second anti-fuse devices being connected in series at the second end of the first anti-fuse device to form a string of anti-fuse devices;
• a first voltage supply bus and a second voltage supply bus;
• a first programming transistor connected between the first voltage supply bus and the first end of the first anti-fuse device;
• a second programming transistor connected between the second voltage supply bus and the second end of the first anti-fuse device;
• a third programming transistor connected between the first voltage supply bus and the second end of the second anti-fuse device;
• and
• a control bus network for turning the first, second and third programming transistors ON and OFF to program selectively one of the first and second anti-fuse devices.

A programmable interconnection architecture for use in a semiconductor chip for programming a targeted anti-fuse device, comprising:

• a plurality of anti-fuse devices connected to each other in series to form a plurality of strings, each anti-fuse device having a first end and a second end and the ends of each string having an open circuit condition;
• a plurality of programming transistors arranged in pairs of first and second programming transistors such that each first end of an anti-fuse device is connected to one first programming transistor and each second end of an antifuse device is connected to a second programming transistor;
• a plurality of voltage supply buses connected to the plurality of programming transistors such that each antifuse device is connected between one first programming transistor and second programming transistor, wherein the one first and second programming transistors are connected to different voltage supply buses;
• and
• a control bus network for turning ON and OFF each of the plurality of programming transistors.

In a circuit for programming an anti-fuse device connected in an interconnection architecture comprised of strings of anti-fuse devices wherein each string comprises a plurality of anti-fuse devices connected in series, and wherein each anti-fuse device has a first and second end and a threshold programming voltage, and wherein each anti-fuse device has an associated pair of programming transistors comprising a first and a second transistor respectively connected to the first and second ends of the anti-fuse device, and wherein a first voltage supply bus for receiving a first voltage is connected to the first transistor and a second voltage supply bus for receiving a second voltage is connected to the second transistor of each pair of transistors in a string, and wherein a control bus network is connected to the transistors for turning them ON and OFF, a method of programming a selected anti-fuse device comprising the steps of:

• supplying a predetermined first voltage to a selected first voltage supply bus;
• supplying a predetermined second voltage to a selected second voltage supply bus, the difference between the first and second predetermined voltages being larger than the threshold programming voltage;
• and
• turning ON a selected pair of programming transistors to program the selected anti-fuse device.

A method of programming one anti-fuse device in a string of anti-fuse devices in which each anti-fuse device has a pair of programming transistors connecting the anti-fuse device between two voltage supply buses comprising:

• (a) applying a first voltage to a first voltage supply bus;
• (b) applying a second voltage to a second voltage supply bus;
• (c) turning ON the pair of programming transistors connecting the one anti-fuse device between the first and second supply buses, thereby to apply the difference between the first and second voltages across the anti-fuse device;
• and
• (d) maintaining at least one programming transistor of each of the other pairs of programming transistors OFF so that no significant differential voltage is applied to the other anti-fuse devices of the string.

A method for programming anti-fuse devices having a first end, a second end and a threshold programming voltage comprising:

• connecting the first end of the anti-fuse device to a first transistor;
• connecting the second end of the anti-fuse device to a second transistor;
• connecting the first transistor to a first voltage supply bus;
• connecting the second transistor to a second voltage supply bus;
• turning ON the first and second transistors;
• and
• applying a first voltage and a second voltage across the anti-fuse device such that the difference between the first and second voltages is greater than the threshold programming voltage.

A circuit for programming an anti-fuse device comprising:

• a first, second, and third anti-fuse devices, each having a first end, a second end, and a threshold programming voltage, the third anti-fuse device being connected between the second end of the first anti-fuse device and the first end of the second anti-fuse device;
• a first voltage supply bus for receiving a first voltage, a second voltage supply bus for receiving a second voltage, a third voltage supply bus for receiving a third voltage, and a fourth voltage supply bus for receiving a fourth voltage;
• a first transistor having an ON and OFF condition connected between the first voltage supply bus and the first end of the first anti-fuse device;
• a second transistor having an ON and OFF condition connected between the second voltage supply bus and the second end of the second transistor;
• a third transistor having an ON and OFF condition connected between the third voltage supply bus and the first end of the second anti-fuse device;
• a fourth transistor having an ON and OFF condition connected between the fourth voltage supply bus and the second end of the first anti-fuse device;
• and
• a control bus network connected to the first, second, third and fourth transistors for selectively turning the same ON and OFF.