Multiple-time programmable electrical fuse utilizing MOS oxide breakdown

摘要

An improved a programmable electrical fuse device utilizing MOS oxide breakdown is described herein. The fuse device comprises a programmable MOS device having a first gate width, a reference MOS device having a second gate width that is substantially less than the first gate width, and a sense amplifier operable to detect a difference in current and generate a corresponding logical signal. According to one embodiment, the fuse device can be programmed only once to invert its logical state and thereby provide a changeable logical signal. This is done by applying an overvoltage signal to the programmable MOS device so that its oxide layer breaks down. Since the programmable MOS device and the reference MOS device are on opposite sides of the sense amplifier, an opposite logical signal is generated by shorting-out the programmable MOS device. According to another embodiment, the fuse device can be programmed and erased multiple times by breaking down oxide layers in MOS devices that are alternating sides of a sense amplifier.