Phase-Change MemoryâTowards a Storage-Class Memory Abstract: Phase-change memory (PCM) has undergone significant academic and industrial research in the last 15 years. PCM is 500 to 1,000 times faster than normal flash memory. Download PDF Abstract: We survey the current state of phase change memory (PCM), a non-volatile solid-state memory technology built around the large electrical contrast between the highly-resistive amorphous and highly-conductive crystalline states in so-called phase change materials. Phase Change Memory Technology Phase change chalcogenides exhibit a revers-ible phase change phenomenon when changed from the amorphous phase to the crystalline phase. Phase change memory (PCM) is an emerging non-volatile memory technology that could play a key role in future computing systems. ST holds a license to the patents that resulted from that original development and has built onto that ground-breaking work for more than 15 years, developing the embedded PCM solution (ePCM) that is today integrated into our 28nm FD-SOI technology platform. After much development, it is now poised to enter the market as a storage-class memory (SCM), with performance and cost between that of NAND flash and DRAM. The technology behind phase-change memory The PCM technology uses a class of materials known as chalcogenides (âkal-kojâuh-nydeâ). The composite material electrically couples the first electrode to the second electrode. Abbreviated as PCM, phase change memory is a type of non-volatile memory that is much faster than the common flash memory, and it also uses up to one-half the power. The cycling endurance of phase-change memory is one of the last hurdles to overcome to enable its adoption in the larger market for persistent memory products. The storage element is a Phase Change Memory (PCM) cell and the selector is an Ovonic Threshold Switch (OTS). The vertically integrated memory cell of one PCM and one OTS (PCMS) is â¦ As shown in Figure 1, in the amorphous phase, the material is highly disordered -- there is an absence of regular order to the crystalline lattice. Chalcogenides are alloys that contain an element in the oxygen/sulphur family of the Periodic Table (Group 16 in the new style or â¦ Moreover, the composite material comprises a phase change material and a resistor material. The memory cell is built by layering a storage element and a selector. Phase-change memory cycling endurance failures, whether they are stuck-SET (caused by elemental segregation) or stuck-RESET (caused by void formation), are caused by atomic migration. In collaboration with RWTH Aachen University, my team and I at IBM Research-Zurich went in the opposite direction of the mainstream PCM research by using only one single chemical elementâantimony (Sb)âinstead of the typical material cocktail. Because no electrical power is required to maintain either phase of the material, so phase-change memory is non-volatile. Phase change memory uses a semiconductor alloy that can be changed rapidly between an ordered, crystalline phase having lower electrical resistance to a disordered, amorphous phase with much higher electrical resistance. A memory cell comprises a first electrode, a second electrode and a composite material. PCM is considered an emerging technology. Phase change memory (PCM) is a type of non-volatile RAM that stores data by changing the state of the material used, meaning it changes back and forth between amorphous and crystalline states on a microscopic level. The fundamental mechanism for Phase-Change Memory was invented in the 1960s by Stanford Robert Ovshinsky.