Modeling and Signal Integrity Analysis of 3D XPoint Memory Cells and Interconnections with Memory Size Variations During Read Operation

Abstract

3D XPoint memory is one of the new memory using phase change memory (PCM) and ovonic threshold switch (OTS) with 20 nm 3-dimensional cross array structure. This memory is non-volatile and has better performance in terms of memory process speed than NAND flash memory and memory density than DRAM. The space between interconnections are close so, the voltage coupling affects to the adjacent interconnections during read operation. In this paper, we analyzed the 3D XPoint memory with memory size variation during read operation considering signal integrity (SI). For the analysis, we assumed the overall structure of the 3D XPoint memory and modeled the memory cell that consist of PCM and OTS as behavior model and the interconnections as RC model with 3D electromagnetic (EM) simulator. We fully simulated the 3D XPoint memory including memory behavior model, RC model of interconnections and peripheral circuits such as the addressor and current sense amplifier. With variation of the memory size during read operation, there are SI issues such as voltage coupling and drop trends through the interconnections.