Reading Guide: There are five main types of emerging non-volatile memory technologies: flash (Flash), ferroelectric random access memory (FeRAM), magnetic random access memory (MRAM), phase-change memory (PCM) and RRAM.
The emerging non-volatile memory has attracted a lot of attention, and these emerging memory technologies will dominate the next generation memory market.
There are five main types of these emerging non-volatile memory technologies:
- Flash (Flash),
- Ferroelectric random access memory (FeRAM),
- Magnetic random access memory (MRAM)
- Phase-change memory (PCM)
Non-volatile memory, especially Flash’s “flash” memory with block (or “sector”) erasure mechanism, has been the fastest-growing part of the semiconductor business over the past decade.
Some of these emerging technologies include MRAM,FeRAM,PCM, self-rotating moment-shifting random access memories (STT-RAM), RRAM and memristors.
MRAM is a non-volatile memory. Unlike DRAM, data is not stored in a charge stream, but in a magnetic storage element. The memory element is formed by two ferromagnetic plates, each of which can maintain a magnetic field and be separated by a thin insulating layer. One of the two plates is a permanent magnet set to a specific polarity. Another field can be changed to match the field of the external field to store memory.
STT-RAM is the upgrade technology of MRAM (non-volatile), but it has better scalability than traditional MRAM.
STT is an effect in which spin polarization current can be used to modify the direction of the magnetic layer in a magnetic tunnel junction or spin valve.
Spin transfer torque technology has the potential to make MRAM devices meet low current requirements and reduce cost.
At present, however, the current required for redirected magnetization is too high for most commercial applications.
PCM is a non-volatile random access memory based on the reversible phase transition between amorphous and crystalline state of chalcogenide glass, also known as electronic unified memory ((OUM),), which can be realized by heating and cooling glass.
It takes advantage of the unique properties of chalcogenide, a material already used to make CD, so the heat generated by the current switches the material between the two states.
Different states have different resistors and can be used to store data.
The ideal storage device or so-called unified memory will meet three requirements at the same time: high speed, high density and non-volatile (retention).
At present, such memory has not yet been developed.
Floating gate nonvolatile semiconductor memory (NVSM) has high density and retention ability, but its programming / erasing speed is low.
DRAM has high speed (about 10 ns) and high density, but it is easy to lose.
On the other hand, SRAM has a very high speed (about 5 ns), but is limited by very low density and volatility.
PCM is expected to be more scalable than other emerging technologies.
RRAM is a non-volatile memory similar to PCM.
The concept of the technology is to make the normally insulated dielectric conductive through a filament or conductive path formed by applying a sufficiently high voltage.
It can be said that this is a memristor technology, and RRAM should be seen as a strong candidate to challenge NAND flash memory.
At present, FRAM,MRAM,PCM and PCM have been put into commercial production, but compared with DRAM and NAND flash memory, they are still limited to special applications.
Some people think that MRAM,STT-RAM and RRAM are the most promising emerging technologies, but they are still many years away from competing for industry adoption.
Any new technology must be able to provide most of the following attributes in order to promote industry adoption on a large scale: the scalability of the technology, the speed and power consumption of the device is better than the existing memory.
NVSM has inspired people’s understanding of the new type of non-volatile memory, which will successfully lead to the realization and commercialization of unified memory.