Phase change memory unit and preparation method thereof

Abstract

The invention discloses a phase change memory unit. The phase change memory unit comprises bottom electrodes, heating electrodes, a phase change unit and a top electrode from bottom to top, and the phase change unit is of a longitudinally arranged cylinder structure and comprises a cylindrical selection device layer, an annular barrier layer and an annular phase change material layer from inside to outside; the plurality of bottom electrodes and the plurality of heating electrodes are in one-to-one correspondence, the bottom electrodes, the heating electrodes and the phase change material layer are sequentially connected, and the selection device layer is connected with the top electrode. According to the invention, the phase change unit and the plurality of heating electrodes are combinedtogether to form a structure that a plurality of phase change resistors share one selection device, and different phase change resistors can be connected with the bottom electrodes positioned on different metal interconnection layers through respective heating electrodes, so that the area of the chip in the horizontal direction is not increased, high-density storage is realized, the phase changematerial and the heating electrodes are very thin, and the power consumption of the device can be effectively reduced.

Description

technical field [0001] The invention relates to the technical field of semiconductor integrated circuit manufacturing technology, in particular to a high-density phase-change memory unit structure and a preparation method thereof. Background technique [0002] With the emergence of a series of new information technologies such as big data, the Internet of Things, cloud computing, and artificial intelligence, requirements for high read / write speed, low power consumption, high storage density, long service life, and high reliability have been put forward for memory. At present, new storage technologies represented by phase-change memory are gradually replacing traditional DRAM and Flash, and have broad application prospects in the fields of artificial intelligence and memory-computing integrated chips. [0003] The existing phase-change memory unit (taking Intel 3DX-point technology as an example) is composed of bottom electrode 01, selection device layer 02, barrier layer 03,...

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Problems solved by technology

[0004]Figure The 3D X-point technology shown in 1 adopts the vertical stacking technology of two layers of phase change units to form high-density storage, but because the phase change material layer 04 in the phase change unit of the first layer is very sensitive to temperature, so When preparing the second-layer phase-change unit, the thermal budget of the process is very limited (less than 350°C), which puts high demands on the material screening and preparation process for selecting the device layer 02 and phase-change material layer 04, which will Affects device performance and yield

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