Overview of candidate device technologies for storage-class memory

TLDR

Storage‑class memory (SCM) merges the high performance and robustness of solid‑state memory with the low‑cost archival capacity of conventional hard disks. This review surveys candidate solid‑state nonvolatile memory technologies that could enable such SCM devices. The authors evaluate technologies capable of ultra‑high areal density, including evolutionary flash extensions such as SONOS and nanotraps, and revolutionary ferroelectric, magnetic, phase‑change, resistive, perovskite, solid‑electrolyte, organic, and polymeric memories, focusing on sublithographic patterning, multi‑bit per cell, and multilayer architectures. They compare the practical scaling potential of each candidate technology toward ultrahigh effective areal density.

Abstract

Storage-class memory (SCM) combines the benefits of a solid-state memory, such as high performance and robustness, with the archival capabilities and low cost of conventional hard-disk magnetic storage. Such a device would require a solid-state nonvolatile memory technology that could be manufactured at an extremely high effective areal density using some combination of sublithographic patterning techniques, multiple bits per cell, and multiple layers of devices. We review the candidate solid-state nonvolatile memory technologies that potentially could be used to construct such an SCM. We discuss evolutionary extensions of conventional flash memory, such as SONOS (silicon-oxide-nitride-oxide-silicon) and nanotraps, as well as a number of revolutionary new memory technologies. We review the capabilities of ferroelectric, magnetic, phase-change, and resistive random-access memories, including perovskites and solid electrolytes, and finally organic and polymeric memory. The potential for practical scaling to ultrahigh effective areal density for each of these candidate technologies is then compared.