与CMOS热兼容的CRAM存储元结构研究

CRAM Cell Structure Thermally Compatible with CMOS Circuits

从硫属相变存储器CRAM(Chalcogenide-based phase-change RAM)的存储原理出发,建立存储元一维多层热传导结构模型。根据存储元的读写功能需求及其与CMOS驱动电路实现热兼容的条件,确定3个临界参数:相变材料熔化温度Tm、相变的临界区域Xc、CMOS驱动电路能承受的临界温度Tc。合理设定边界条件,利用差分法编程求解多层热传导方程得出温度分布曲线图。在临界参数的限制下,通过选择调整存储元的电极、隔热层、相变层的材料尺寸,并使用加热层对相变层进行加热,设计出的CRAM存储元结构模型不仅满足了CRAM存储元的存储读写要求,而且首次实现了CRAM存储元与CMOS电路的热兼容。

A one-dimensional multi-layer heat conduction model of CRAM is developed based on its memory principle. According to the read/write requirement of memory cell, and to the condition of its thermal compatibility with CMCIS circuits, the critical parameters are fixed on. The temperature profiles are portrayed by solving the heat conduction equation with the reason- able boundary conditions. Under the limitation of the critical parameters, we adjust the parameters of cell structure, use heating layer, and then develop the structural model of CRAM memory cell which not only meet the need of read/write function of memory cell but for the first time achieve the thermal compatibility of CRAM memory cell with CMOS circuits.