Advanced Memory

Phase Change Memory (PCM) devices offer high density of storage relative to DRAM, and can help increase main memory capacity of future computer systems while remaining within the costs and power constraints. PCM based on composite of chalcogenide which depends on reversible transition between two different resistance values. Ge2Sb2Te5 is a famous composite of chalcogenide. Atoms of chalcogenide are O, S, Se, Te etc. Composite of chalcogenide has a special property that changes own lattice structure between amorphous and crystalline structure when it was heated. In amorphous structure, PCM has high resistance and in crystalline structure, PCM has low resistance. Therefore, PCM could save data and be used as non-volatile memory without any transistor or capacitor.

ReRAM have many advantages that are fast switching speeds, non-volatile, low power consumption, high endurance and simple to manufacturing. Resistive switching Random Access Memory (RRAM) which based on metal oxides depends on reversible transition of the active material between two different resistance values.

ReRAM have many advantages that are fast switching speeds, non-volatile, low power consumption, high endurance and simple to manufacturing. Resistive switching Random Access Memory (RRAM) which based on metal oxides depends on reversible transition of the active material between two different resistance values. Basically, ReRAM has MOM (Metal Oxide Metal) structure. Oxide layer consists of oxidized metal. So it is not conductive. When ReRAM is biased between both metal layer, oxygen of oxide layer is ionized and then ionized oxygen move positive electrode. In location of ionized and moved oxygen, oxygen vacancy that called filament occur. When filament appear, Current can flow through oxide layer because ReRAM have low resistance. If ReRAM is biased between both metal layer the other way, oxygen ions come bake own location and filament disappear. In this state, current could not flow because ReRAM has high resistance. ReRAM could be used non-volatile memory without any transistor or capacitor.

The 3D X-Point is a non-volatile memory technology released by Intel and Micron in July 2015. Intel uses a technology called “Optane” to refer to the next memory device, while Micron uses the name QuantX. The density of storage is similar to flash memory, but 3D X-Point Is known to have improved durability and faster operating speed. 3D X-Point storage is based on a change in the resistance of massive materials with a stackable grid-like data access array.