A 1s1r type phase change memory unit structure and its preparation method

Abstract

The invention discloses a 1S1R type phase-change memory cell structure and a preparation method thereof. A top electrode layer, an OTS layer, an intermediate electrode layer, an insulating layer, a bottom electrode layer and a substrate are sequentially stacked; the intermediate electrode layer and the insulating layer The middle part of the contact surface is recessed into the middle electrode layer, and the recess is disposed with a phase change material layer; the insulating layer is provided with a heating electrode penetrating through the insulating layer at a position corresponding to the phase change material layer, and one end of the heating electrode is connected to the phase change material layer, and the other end is connected to bottom electrode layer. The advantage is that the wrapped middle electrode layer is adopted, and the heat distribution is more uniform by adjusting the diameter and height of the phase change material layer according to the heat distribution shape of the mushroom-shaped unit. The contact area between the phase change material layer and the intermediate electrode layer is increased, thereby reducing the current density of the phase change material in the contact area with the intermediate electrode layer, avoiding the local programming of the area by mutation heat, improving the resistance distribution, and reducing misoperation It is possible to improve the reliability of the phase change memory unit.

Description

technical field [0001] The invention relates to a nanoscale phase-change memory unit structure, in particular to a 1S1R type phase-change memory unit structure. [0002] The invention also relates to a preparation method of a nanoscale phase-change memory unit structure, in particular to a preparation method of a 1S1R type phase-change memory unit structure. Background technique [0003] Phase change materials were used in optical discs in the early days, and later became a research hotspot of PCRAM (phase change random access memory) even today. In the field of electrical storage, since Flash, the current mainstream non-volatile memory, will encounter its own physical bottleneck at about 20nm node, seeking the next generation of non-volatile memory has become the main line of development in the storage field. According to the research of Marissa A. Caldwell et al., when the three-dimensional size of the phase change material is 2nm-5nm, it can still exhibit phase change ch...

AI Technical Summary

Problems solved by technology

The heat generated in the above problems will cause more inactive regions of the phase change material to melt, that is, expand the area of ​​the "mushroom-shaped" active region, affect the cell resistance distribution, and thus reduce the reliability of the cell

Images