CMOS Antifuse NVM Security
To date, Kilopass’ embedded non-volatile memory cannot be hacked using passive, semi-invasive, and invasive methods. Due to the nature of the technology, it is difficult to determine the content of the memory. Passive techniques including using current profiles to determine the word pattern are unsuccessful because the bitcell current for “0”s and “1”s are much smaller than the current required for sensing or to operate the peripheral circuits in order to read the memory. One cannot determine the pattern of the word being read. Invasive techniques including backside attacks or SEM passive voltage contrast are unsuccessful because it is very difficult to isolate the bitcell since it is connected in a cross point array. Furthermore, it is difficult using chemical etching or mechanical polishing to locate the oxide breakdown. In a cross section or a top view, it is difficult to determine which bit is programmed.