International Business Machines Corporation
On-chip security key with phase change memory

Abstract:

A method is presented for forming an on-chip security key. The method includes electrically connecting a pair of phase change memory (PCM) elements in series, electrically connecting a programming transistor to the pair of PCM elements, electrically connecting an input of an inverter to a common node of the pair of PCM elements, setting the PCM elements to a low resistance state (LRS) in an initialization stage, applying a RESET pulse to generate a security bit and to cause one of the PCM elements to change to a high resistance state (HRS), and generating a logic "1" or "0" at the output of the inverter.