Micron Technology Incorporated

Dien S Luong

Kurt D Beigel

Patrick J Mullarkey

Douglas John Cutter

Fan Ho

Kim M Pierce

Brett M Debenham

Adrian E Ong

Todd A Merritt

Jeffrey P Wright

Michael Amiel Shore

Hua Zheng

Method and apparatus are disclosed for checking the resistance of antifuse elements in an integrated circuit. A voltage based on the resistance of an antifuse element is compared to a voltage based on a known resistance, and an output signal is generated whose binary value indicates whether the resistance of the antifuse element is higher or lower than the known value of resistance. The method and apparatus are useful in verifying the programming of antifuse elements.

Method and apparatus for checking the resistance of programmable elements

An integrated circuit memory device has a plurality of nonvolatile programmable elements which are used to store a pass/fail status bit at selected milestones in a test sequence. At selected points in the test process an element may be programmed to indicate that the device has passed the tests associated with the selected point in the process. Prior to performing further tests on the device, the element is read to verify that it passed previous tests in the test process. If the appropriate elements are not programmed, the device is rejected. A rejected device may be retested according to the previous test steps. Laser fuses, electrically programmable fuses or antifuses are used to store test results. The use of electrically writeable nonvolatile memory elements allows for programming of the elements after the device has been packaged.

Method and apparatus for storage of test results within an integrated circuit

Method and apparatus are disclosed for reducing antifuse programming time by connecting the programming voltage to the electrode of the antifuse element that has roughened polysilicon.

Method and apparatus for reducing antifuse programming time

Method and apparatus are disclosed for checking the resistance of programmable circuits in an integrated circuit where each programmable circuit includes a programmable element, such as an antifuse. A precharged node is connected to the programmable element and the voltage at the node discharges based on the resistance of the programmable element. An output signal is produced whose binary value is based on the voltage at the node after a sufficient time has elapsed to allow the initial voltage to discharge based on the resistance of the programmable element.

An antifuse bank includes a bank of self-decoupling anti fuse circuits. The anti fuse circuits are programmed according to a pattern of address bits by blowing antifuses corresponding to bits of the address. The antifuses are blown by applying a high voltage across the antifuse. As each antifuse is blown, its resistance drops and current through the antifuse increases. The self-decoupling circuit detects the increased current flow and, when the anti fuse resistance is sufficiently low, limits current flow through the anti fuse. The antifuse thus does not load the high voltage source as other antifuses are blown.

Self current limiting antifuse circuit

An antifuse bank includes a bank of self-decoupling antifuse circuits. The antifuse circuits are programmed according to a pattern of address bits by blowing antifuses corresponding to bits of the address. The antifuses are blown by applying a high voltage across the antifuse. As each antifuse is blown, its resistance drops and current through the antifuse increases. The self-decoupling circuit detects the increased current flow and, when the antifuse resistance is sufficiently low, limits current flow through the antifuse. The antifuse thus does not load the high voltage source as other antifuses are blown.

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Boise, ID, United States of America

Dien S Luong