Double-layer phase change resistance and forming method thereof as well as phase change memory and forming method thereof

Abstract

The invention relates to a double-layer phase change resistance and a forming method of the double-layer phase change resistance as well as a phase change memory and a forming method of the phase change memory; the forming method of the double-layer phase change resistance comprises the following steps of: providing a substrate, and forming a first layer of phase change resistance on the substrate; forming a first dielectric layer with a first opening on the first layer of phase change resistance, wherein the first opening exposes the first layer of phase change resistance; forming a second dielectric layer, and covering the side wall of the first opening, wherein a second opening is formed by the second dielectric layer in a surrounding manner; forming a third dielectric layer in the second opening, and forming an annular opening between the third dielectric layer and the second dielectric layer; and forming a second layer of phase change resistance which covers the first dielectric layer, the second dielectric layer and the third dielectric layer and fills the annular opening. According to the forming method of the double-layer phase change resistance, the key size of a connecting part between the second layer of phase change resistance and the first layer of phase change resistance is ensured to be small, the performance of a PCRAM (Phase Change Random Access Memory) is increased, the reset current can be reduced, and the setting speed is improved.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to a method for forming a double-layer phase-change resistor in a phase-change memory, a double-layer phase-change resistor, a method for forming a phase-change memory, and a phase-change memory. Background technique [0002] With the development of information technology, the demand for storage devices is increasing, which promotes the development of storage devices in the direction of high performance, low voltage, low power consumption, high speed and high density. Phase change memory (PCRAM, phase change Random Access Memory) is a new generation of non-volatile memory developed on the basis of CMOS integrated circuits, which uses an alloy of one or more elements of group V or group VI in the periodic table As a phase-change resistor, the phase-change resistor is used as a memory unit, and the phase-change resistor can quickly change from an ordered crystalline state (low ...

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Problems solved by technology

[0005] The problem solved by the present invention is that it is difficult to obtain an opening with a small critical size when forming a double-layer phase change resistor

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