Samsung sees size and power benefits in phase-change memory (PCM), a memory type that is being pushed as a replacement for memory that goes into devices like mobile phones today.
For years, the semiconductor company has been researching PCM, which is considered an experimental memory type. PCM involves glass-like material that changes states as atoms are rearranged. The state of the material corresponds to the 1s and 0s in computing, allowing it to be used to store data.
Many companies including Intel and Infineon Technologies have separately been involved in PCM’s development for many years, trying to reduce size, while improving speed and storage capacity. Proponents have argued that PCM could eventually take the place of NAND and NOR flash memory types being used in mobile devices.
PCM chips will initially find use in mobile devices like handsets and ultimately provide a 30 percent reduction in power consumption and a 40 percent “space shrink” when changing memory parts from NOR flash to PCM, said Harry Yoon, senior manager of technical marketing of Samsung Semiconductor.
Samsung has started production of 512 megabit PCM chips, Yoon said. Production of the chips will rise with customer demand.
There is a lot of momentum behind the development of PCM, but the memory type is still being researched and needs years to replace existing memory types in mobile devices, analysts said. It could take many years to make its mark in mobile devices, said Jim Handy, an analyst at Objective Analysis, a semiconductor market research firm.
PCM may become feasible at a certain manufacturing process, Handy said, which could take 12 years, he said. Right now, memory production processes are at 34 nanometers, and the process needs to go down to 10 to 12 nanometers, Handy said.
PCM could initially replace NOR flash in devices like smartphones, analysts said. Compared to NOR, PCM offers faster data access and endurance, said Gregory Wong, an analyst with Forward Insights. PCM also offers significant power savings compared to existing memory types.
PCM may have a tougher time dislodging NAND flash, which is used to store images and movies on devices like smartphones, Handy said. NAND could have enough of a price advantage to hinder PCM adoption.
Toshiba recently showed it could make NAND flash using the 10-nanometer process. NAND could compete with PCM as chip sizes continue to shrink, Handy said. But NAND flash will reach the end of its line at some point, which is when PCM or competing memory technologies could take off.
Wong said PCM also has to overcome development and cost-related issues in the short term. For example, NOR flash stores two bits per cell, while PCM stores only one bit, which pushes up development costs.
“They are going to have to be able to aggressively shrink the memory cell in order for it to be cost competitive with NOR,” Wong said.
Nevertheless, Samsung’s production announcement is a significant milestone for PCM’s future, analysts said.
“What they seem to be implying is that they’ve gone from something that was a lab curiosity to something they believe can be mass produced,” Handy said. “It implies they saw a brighter future for PCM than other technologies.”
Numonyx — a joint venture between STMicroelectronics and Intel — has already commercially shipping PCM devices code-named “Alverstone” in small numbers. Samsung and Numonyx earlier this year announced the companies would jointly develop PCM specifications.
There are other technologies beyond PCM being researched as an alternative to flash memory, including MRAM (magnetoresistive random access memory) and RRAM (resistive random access memory).