Demonstration of Reliable Triple-Level-Cell (TLC) Phase-Change Memory

Although phase-change memory is admittedly the most mature of the emerging nonvolatile memory technologies, its eventual mass production and market adoption may depend on its cost, in particular in comparison to DRAM and to NAND Flash. In addition to process complexity, another major factor that affects the cost of a memory technology is the capability to store multiple bits per memory cell. As a notable example, Triple-Level-Cell (TLC) NAND Flash is currently leading the Flash capacity shipments. With this as motivation, we present a combination of electrical sensing techniques and signal processing technologies to demonstrate, for the first time, the viability of reliable, nonvolatile, TLC storage in phase-change memory cells after extended endurance cycling and temperature stress.