Samsung introduced a new memory technology called Selective Only Memory (SOM), which combines persistence and high read/write speed similar to DRAM, as well as the possibility of “expandability.” The company used advanced computer modeling techniques to accelerate the development of SOM.

SOM is based on phase change memory using stacked electrode arrays and cross-point memory architectures similar to RRAM. Typically these architectures require a selector transistor or diode to address specific memory cells.

The company took a new approach by investigating chalcogenide-based materials that function as both selective and memory elements, introducing a new form of permanent memory. Samsung researchers will present their findings at the International Electronic Device Meeting (IEDM), to be held in San Francisco from December 7-11 this year.

The South Korean tech giant screened a wide range of chalcogenide materials for SOM applications, examining more than 4,000 material combinations and narrowing them down to 18 using initial computer simulations. The focus was on improving the threshold voltage drift and optimizing the memory window, two important factors in SOM performance.

Traditional SOM research was limited to the use of chalcogenide systems of Ge, As, and Se found in Ovon threshold switches (OTS). But Samsung says its extensive modeling process allowed it to take a closer look at the device’s communications capabilities, thermal stability and reliability to improve performance and efficiency.

In the next IEDM presentation, IMEC researchers will discuss potential atomic mechanisms, such as local rearrangement of atomic bonds and atomic dissociation, that could explain how the selective component of the SOM works and further influence the threshold voltage, an important factor in memory performance.