Phase change memory and its preparation method

Abstract

The invention discloses a phase change memory and a preparation method thereof, in particular, a fine pitch phase change random access memory (PCRAM) design and a preparation method thereof. In one embodiment, a phase change memory (PCM) cell includes a spacer defining a rectangular reaction region and a phase change material layer disposed in the reaction region. The above-mentioned phase change memory unit also includes a protective layer disposed on the germanium antimony tellurium (GST) thin film layer and disposed within the area defined by the spacer, and a capping layer is disposed on the above-mentioned protective layer and above the spacers mentioned above. The present invention enables reducing the size of the actual reaction area of ​​a phase change memory cell.

Description

technical field [0001] The invention relates to a phase change memory, in particular to a fine phase change random access memory. Background technique [0002] Recently, alternative nonvolatile memory devices, such as phase change random access memory (PCRAM) devices, magnetic random access memory (magnetic random access memory, MRAM) devices, and cell structures and dynamic random access A ferroelectric random access memory (FRAM) similar to a dynamic random access memory (DRAM) device has been proposed and is under development. A memory cell of a phase change random access memory (PCRAM) generally includes a phase change element including a chalcogenide alloy such as germanium antimony tellurium (Este or GST), and A structure, such as a transistor or other device that utilizes electrical current in a phase change element. In one embodiment, one of the sources / drains of the above-mentioned transistors may be coupled to ground, the other source / drain may be coupled to the ...

AI Technical Summary

Problems solved by technology

In addition, the recent processes described above for fabricating phase change random access memory (PCRAM) cells can induce voids in the germanium antimony tellurium (GST) layer due to poor Sealing layer coverage leads to outgassing of GeSbTe at high temperature

In particular, poor step coverage will induce voids in the germanium antimonytellurium (GST) layer, and when high temperatures (eg, greater than 250° C.) are used at the back end of the above process, outgassing the situation will get worse

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