The programmable metallization cell, or PMC, is a non-volatile computer memory developed at Arizona State University. PMC a technology developed to replace the widely used flash memory, providing a combination of longer lifetimes, lower power, and better memory density. Infineon Technologies, who licensed the technology in 2004, refers to it as conductive-bridging RAM, or CBRAM. CBRAM became a registered trademark of Adesto Technologies in 2011. NEC has a variant called “Nanobridge” and Sony calls their version “electrolytic memory”.
PMC is a two terminal resistive memory technology developed at Arizona State University. PMC is an electrochemical metallization memory that relies on redox reactions to form and dissolve a conductive filament. The state of the device is determined by the resistance across the two terminals. The existence of a filament between the terminals produces a low resistance state (LRS) while the absence of a filament results in a high resistance state (HRS). A PMC device is made of two solid metal electrodes, one relatively inert (e.g., tungsten or nickel) the other electrochemically active (e.g., silver or copper), with a thin film of solid electrolyte between them.
The resistance state of a PMC is controlled by the formation (programming) or dissolution (erasing) of a metallic conductive filament between the two terminals of the cell. A formed filament is a fractal tree like structure.
PMC rely on the formation of a metallic conductive filament to transition to a low resistance state (LRS). The filament is created by applying a positive voltage bias (V) to the anode contact (active metal) while grounding the cathode contact (inert metal). The positive bias oxidizes the active metal (M):