This may be another important advantage that OUM has. This patent application shows how individual cells can be blown like a fuse electrically to either eliminate a defective cell, and transfer it's duty to one cell of a redundant array of cells, or to customize a chip.
"The present invention is directed to a method of operating a programmable resistance memory element so that the programmable resistance memory element may be operated as a fuse. Hence, a fuse is achieved through programming of a programmable resistance memory element rather than through the special requirement of a laser or special thin film....
....[0054] Programmable resistance memory elements may be used for chip repair. For example, they may be used to convert partially defective die into fully functional die by routing addresses from defective rows and columns to redundant functional rows and columns. This can be done late in the process after packaging, after burn-in, or after high-speed sort in order to route around defective rows and columns as determined or brought out by these later steps."
and
"Hence, using the BLOWN state allows for information (such as the die routing and die customization information, memory cell repair information, and even the microcode for the microcontroller) to be more permanently stored in a programmable resistance element by blowing it open and placing it in the BLOWN state. The present invention may thus be used as a way to more permanently personalize an integrated circuit chip (such as a nonvolatile memory chip or even a volatile memory chip) wherein information about the chip is stored in a programmable resistance element by placing the programmable resistance element into the BLOWN state. Placing the information in a programmable resistance element that has been programmed into the BLOWN state may ensure that the information will remain in the programmable resistance element even though additional energy (such a programming pulses or heat) enters the programmable resistance material. The programmable resistance elements placed in the BLOWN state may be used to more reliably store information including, but not limited to, identification information and even memory chip control timing."
appft1.uspto.gov
IMO, it effectively eliminates the need to make "perfect" chips. If there are one or two bad boys in there, they can be zapped and replaced by a substitute. Or certain information that you don't ever want to change can be "hard wired". I believe that this has to be done with a laser in conventional chips.
Good show.
Del |
