High-reliability phase change material, phase change memory and preparation method

Abstract

The invention discloses a high-reliability phase change material, which is a superlattice-like phase change material layer formed by circularly and alternately overlapping first phase change materiallayers and second phase change material layers, wherein a superlattice-like interface is formed between the first phase change material layer and the second phase change material layer, the first phase change material layer is Sb2Te3 as an induction layer, the second phase change material layer is Ge15Te85, and at least three layers of the first phase change material layers and the second phase change material layers are circularly and alternately overlapped. The amorphous Sb2Te3 layer requires low energy for crystallization, stable lattice orientation is easy to form, the selected Sb2Te3 layer can thus be used as the induction layer, the amorphous Ge15Te85 layer has a higher phase change speed in the phase change process, and rapid crystallization of the whole phase change material can bepromoted; in addition, in the energy band structure of the selected Ge15Te85 layer, the defect state is mainly located in the local state of the band tail instead of the defect energy level near theFermi level in the band gap, resistance drift caused by relaxation of the defect energy level is avoided, and therefore the phase change speed is higher in the phase change process.

Description

technical field [0001] The invention belongs to the field of microelectronics, and in particular relates to a high-reliability phase-change material and a preparation method thereof, a phase-change memory using the high-reliability phase-change material and a preparation method thereof. Background technique [0002] As a new type of memory, phase-change memory perfectly fills the device gaps in the current memory architecture due to its appropriate storage density, erasing speed and power consumption. Moreover, because the preparation process of phase change memory is highly compatible with the current CMOS, it is one of the best solutions for the next generation memory architecture, and it has huge potential in high density, high speed, low power consumption, embedded applications and special environment applications. commercial potential. [0003] Phase-change memory uses phase-change materials as storage media. The Joule heat generated by electric pulses changes the resi...

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Problems solved by technology

[0008] However, since the resistance drift of phase change materials is determined by the intrinsic properties of the material and has nothing to do with the size of the material and the device on a spatial scale beyond 10 nm, the optimization of the device structure cannot essentially reduce the resistance drift of the phase change memory.

On the one hand, the improvement of reading and writing methods increases the cost of peripheral circuit design, and on the other hand, it will reduce the speed of reading and writing.

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