Three-Dimensional Phase Change Memory Architecture with Cylindrical Sidewall Electrodes

Next-generation computing system beyond the von Neumann architecture requires the development of new hardware components, and memristive devices have been studied to meet such requirements. As a non-volatile memristor unit, phase-change memory (PCM) is highlighted with the proved nano-second level of fast operation speed and reliable device performances with simple fabrication process using conventional complementary metal-oxide semiconductor (CMOS) technology. Thus, it holds a high potential as non-volatile storage and neuromorphic memory devices, but it still requires device-level innovation for ultra-low operation energy and high-density memory cell arrays beyond the widely adopted 2-dimensional planar device configuration, known as mushroom type PCM. In this work, we propose a new three-dimensional (3D) memory architecture with cylindrical sidewall electrode contacts named heater-all-around phase-change memory (HAA-PCM). With the new design principle, it shows effectively low operation energy (~1 nJ) compared with the conventional PCM devices in the identical 0.18 μm node CMOS fabrication technology. Our 3D HAA-PCM architecture can be applicated to the next-generation artificial intelligence (AI) memory which requires ultra-low operation energy and high-density memory cell.