Anti-fuses often are utilized to customize functionality of an integrated circuit device (e.g., by setting a particular mode or trimming an output), reroute circuitry around a defective element, or as backup elements to improve production yield. Anti-fuses, when programmed or “blown,” change from a high resistance state to a low resistance state. An oxide layer having a low breakdown voltage between conducting layers conventionally is used to implement an anti-fuse. Upon application of a program voltage between the conducting layers that is higher than the oxide breakdown voltage, oxide rupture occurs at the oxide layer, thereby creating a conductive path between the conductive layers and thus changing the anti-fuse to a low resistance state.
Due to the limited range of program voltages that can be applied to an integrated circuit, it typically is desirable to utilize the thinnest type of oxide for a particular IC fabrication process that is available and the oxide type is selected so that the oxide breakdown voltage is lower than the maximum voltage that the devices in the IC fabrication process can endure. However, due to relatively thin oxide layers with relatively low oxide breakdown voltages, anti-fuses typically are fragile and may blow when a proximate anti-fuse is being programmed due to parasitic capacitance coupling between the anti-fuses.
USPTO Backgrounds
USPTO Backgrounds