PCRAM is a memory that utilizes the phase change of a material. While there are currently many areas that need improvement, various companies and governments are leading the way in rapidly developing the technology. In line with the trend of explosive growth in the volume of data that needs to be accommodated, PCRAM is expected to play a key role in various fields.

▲ 512MB PCRAM chip (Photo = Samsung Electronics)

- Required Skills -

The major issues in PCRAM design and production are as follows.

- Sidewall damage due to differences in etch rates among the materials constituting GST
Wearing or Bowing (inward bending)

- High Aspect Ratio Removal of etching residues without affecting structure and oxide film

- As cells become more concentrated, the GST area decreases, whereas the damage area does not decrease.
Therefore, the damage ratio relative to the total area increases.

- If it is not possible to secure the normal GST area, the reliability of the signal decreases.

- </If the span is 30nm or lower, cell interference occurs, and data retention capability decreases due to degradation.

- When voltage is applied to the GST material while it is melted by heat, atomic migration occurs,
The phenomenon of a void (empty space) forming

Even if the production process is similar to that of DRAM, achieving integration below a certain level remains difficult due to the inherent problems mentioned above. Currently, companies and the government are demonstrating a determination to overcome this issue through continuous research and development. However, it will still take some time before mass production is possible.

▲ The process of void defects forming in GST (Source: Sungkyunkwan University IEM Lab, published in NPG Asia Materials)


- Application Areas -

PCRAM is expected to be used for various purposes, including wearable devices, mobile, AI, and IoT. Due to the advantage of being able to operate even in high-temperature environments, ePCM is expected to be actively utilized as an embedded memory, specifically as a vehicle's MCU (Micro Controller Unit).

In addition, along with ReRAM, it will be used as a Storage Class Memory (SCM) to replace server DRAM and a portion of the flash memory used in storage devices (SSD/HDD), improving both operating speed and power consumption.

Furthermore, it is attracting attention as a core component of in-memory computing technology that requires support for high-performance processing, such as big data.

▲ Inactive memory to be the core of next-generation memory (Image=IBM)

- Market Outlook -

The PCRAM market is expected to show strength as stand-alone memory. Stand-alone memory refers to a design and manufacturing method that is engineered and manufactured solely for memory purposes, rather than being integrated with a CPU like in embedded systems. In particular, the PCRAM market is expected to continue its rapid rise from the point when mass production of sizes below 30nm becomes possible.

▲ Next-generation memory market trends (Source: Yole Développement)

French market research firm Yole Développement forecasts that the memory market will grow to about 20 times the level of 2018 in 2023.