Phase change memory cell and manufacturing method thereof

Abstract

The invention relates to a phase change memory cell and a manufacturing method thereof. The phase change memory cell comprises a substrate; the lower electrode is arranged in the substrate, and the upper contact surface of the lower electrode is exposed out of the substrate and is flush with the upper surface of the substrate; the horizontal part of the phase change material layer is connected with the lower electrode, and the phase change material layer is in an L shape; the filling material is arranged above the vertical part of the phase change material layer, and forms a phase change storage structure together with the phase change material layer; and the upper electrode is arranged above the phase change material layer. According to the invention, the phase change area of the phase change memory unit can be effectively reduced.

Description

Technical field [0001] The present invention relates to the field of microelectronics, and in particular, to a phase change memory unit and a method of fabricating it. Background technique [0002] The phase change memory technology is based on Ovshinsky in the late 1960s (Phys.Rev.let., 21, 14501453, 1968), the phase change film proposed by the apple (Phys.let., 18, 254257, 1971) The idea of ​​being used to phase-changing storage media is established, which is a storage device that is inexpensive and stable. The phase change memory can be done on the silicon wafer substrate, and its key material is a recordable phase change film, the heating electrode material 11, the heat insulating material, and the research hotspot of the electrode material are also surrounded by the device process: the physical mechanism of the device , Including how to reduce device materials, etc. The basic principle of phase change memory is to utilize electrical pulse signals on the device unit, so that ...

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Problems solved by technology

At present, most of the institutions engaged in the research and development of phase change memory in the world are large companies in the semiconductor industry. One of their focuses is how to reduce the size of the heating electrode of phase change memory. At present, Samsung's side wall contact is more commonly used. Type heating electrode (Proc.Symp.Very Large Scale Integr. (VLSI) Technol.,2003:175-176), ring heating electrode (Jpn.J.Appl.Phys.,2006,45(4B):3233-3237) With blade-shaped heating electrodes (IEEE Conference Proceedings of International Electron Devices Meeting, 2011, 3.1.1-3.1.4) and STMicroelectronics’ μ-type heating electrodes (Proc. Symp. Very Large Scale Integr. (VLSI) Technol., 2004 ,3.1:18-19), but the disadvantage of the above structure is that it mainly relies on reducing the electrode size to achieve low power consumption, while the size of the phase change material is relatively large, and the gating tube has a significant impact on the density of the phase change memory. OTS (Ovonic Threshold Switching, Ovonic Threshold Switching, Ovonic Threshold Switching) as a new type of gating device can greatly increase the density of memory, it is necessary to propose a new nano-device unit structure to solve the above technical problems

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