Designing Conductive‐Bridge Phase‐Change Memory to Enable Ultralow Programming Power

Abstract

Phase‐change material (PCM) devices are one of the most mature nonvolatile memories. However, their high power consumption remains a bottleneck problem limiting the data storage density. One may drastically reduce the programming power by patterning the PCM volume down to nanometer scale, but that route incurs a stiff penalty from the tremendous cost associated with the complex nanofabrication protocols required. Instead, here a materials solution to resolve this dilemma is offered. The authors work with memory cells of conventional dimensions, but design/exploit a PCM alloy that decomposes into a heterogeneous network of nanoscale crystalline domains intermixed with amorphous ones. The idea is to confine the subsequent phase‐change switching in the interface region of the crystalline nanodomain with its amorphous surrounding, forming/breaking “nano‐bridges” that link up the crystalline domains into a conductive path. This conductive‐bridge switching mechanism thus only involves nanometer‐scale volume in programming, despite of the large areas in contact with the electrodes. The pore‐like devices based on spontaneously phase‐separated Ge13Sb71O16 alloy enable a record‐low programming energy, down to a few tens of femtojoule. The new PCM/fabrication is fully compatible with the current 3D integration technology, adding no expenses or difficulty in processing.

Understanding the Origin of Low-Energy Operation Characteristics for Cr2Ge2Te6 Phase-Change Material: Enhancement of Thermal Efficiency in the High-Scaled Memory Device

“…Filled circles indicate the experimentally obtained values in this study. Orange, blue, and green triangles indicate the plot for GST with GNR electrode, GST with CNT electrode, and conductive-bridge PCM. ,,, Blue and red open squares indicate the assumed operation energy in the product. (d) Cyclic endurance characteristic for the CrGT-based cell with 34 × 34 nm 2 .…”

“…These findings clearly demonstrated that scaling down can significantly lower operation energy. Meanwhile, Yang et al recently showed that conductive-bridge PCM allows for the realization of extremely low operation energy even in large contact area . An approach to microstructure engineering by phase separation in conductive-bridge PCM is a new strategy to reduce operation energy by limiting the phase change region.…”

“…Meanwhile, Yang et al recently showed that conductive-bridge PCM allows for the realization of extremely low operation energy even in large contact area. 34 An approach to microstructure engineering by phase separation in conductive-bridge PCM is a new strategy to reduce operation energy by limiting the phase change region. This study suggests that further operation energy reduction for the CrGT through microstructure engineering can be realized.…”

Tailoring the oxygen concentration in Ge-Sb-O alloys to enable femtojoule-level phase-change memory operations

“…In early 2022, we have designed a conductive-bridge phase-change memory (cbPCM) scheme [73] that combines the advantages of phase-change memory with filamentaryswitching in metal oxides. The essential idea is to minimize the active switching volume in conventional devices via phase separation.…”

Computational understanding role of vacancies and distortions in wurtzite ferroelectric memory materials: implications for device miniaturization

“…4 Thus, the development of next-generation hardware has been an important area of research. [5][6][7] Among them, edge computing, utilizing the same device structure for rapid operations and data storage, is presenting itself as an excellent hardware design to tackle portable, data intensive applications. 8 The success of this approach depends on finding an excellent material platform capable of utilizing the full potential of this design.…”