A ZN-SB-TE phase transformer-changing film material and preparation method for phase-changing memory

Abstract

The invention discloses a Zn-Sb-Te phase change storage thin-film material for a phase change memory and a preparation method of the Zn-Sb-Te phase change storage thin-film material. The Zn-Sb-Te phase change storage thin-film material is characterized in that the material is made of three elements of Zn, Sb and Te, and the chemical structural formula of the material is ZnX (Sb2Te3)(100-X), wherein 0<x<40. The preparation process comprises the steps as follows: a zinc elemental target is mounted into a magnetic control direct current sputtering target, and an Sb2Te3 target is mounted into a magnetic control radio-frequency sputtering target; a sputtering chamber is subjected to vacuum pumping treatment until the vacuum degree inside the chamber reaches 1.6*10<-4> Pa, and then high-purity argon is fed into the sputtering chamber until the air pressure reaches 0.3 Pa; and the sputtering power of the zinc target is controlled to be 0-10 W, the sputtering power of the Sb2Te3 target is controlled to be 60-100 W, and a coating is sputtered for 200 seconds at a room temperature. The Zn-Sb-Te phase change storage thin-film material has the advantages of high crystallization speed, high crystallization temperature, lower melting point, higher crystalline state resistivity, better data retentivity and capability of stably working at high temperatures.

Description

technical field [0001] The invention relates to the technical field of phase-change storage materials, in particular to a Zn-Sb-Te phase-change storage thin film material for phase-change storage and a preparation method thereof. Background technique [0002] Phase Change Random Access Memory (PRAM), also known as Ovshinsky Electric Effect Unified Memory, is based on the Ovshinsky Electric Effect memory proposed by American Ovshinsky in the late 1960s. The storage media of this type of memory are many Chalcogenide compounds are the main ones, which can achieve reversible phase transitions under thermal induction, that is, transitions between amorphous and polycrystalline. In the research and development of PRAM, the phase change material as a storage medium is the core of pulse code modulation (PCM), and its performance optimization is crucial to improving the performance of PRAM devices. Mainstream phase change materials Te-based chalcogenides used in PRAM include Sb-Te, G...

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Problems solved by technology

[0003] At present, the traditional phase change memory materials used in phase change memory are mainly Ge 2 Sb 2 Te 5 , but due to its low crystallization temperature (about 150°C), traditional Ge 2 Sb 2 Te 5 The data of the PRAM storage unit whose material is the storage medium can only be stored at 70-110°C for 10 years, and the data storage life at high temperature is short and needs to be improved

Compared with traditional Ge 2 Sb 2 Te 5 Phase-change memory materials, Si-Sb-Te has shown relatively excellent performance, such as the invention patent named Si-Sb-Te material for phase-change memory (publication number is CN102130298A), it discloses based on the element Si, Sb, Te phase change material, the increase of Si content in this material can improve the data retention of the material, and its crystallization temperature can also reach about 277°C, but the distribution of Si element in the film is not very uniform, which will cause problems in the process of reading and writing. Instability of data; the invention patent named Al-Sb-Te series phase change material for phase change memory (publication number is CN102134698A), discloses a phase change material based on elements Al, Sb, Te, which has than traditional Ge 2 Sb 2 Te 5 The material has a higher crystallization temperature, better thermal stability and data retention and a lower melting point, but the phase transition point of the material from amorphous to crystalline state under thermal induction is not obvious, which will affect PRAM The speed and reliability of data access; and some emerging phase change storage materials mainly include Ga-Sb-Te, N-Sb-Te, Cu-Sb-Te, Ti-Sb-Te, W-Sb-Te, etc. series, among the new phase change materials mentioned above, Ga-Sb-Te, Cu-Sb-Te, Ti-Sb-Te, W-Sb-Te, etc. have a small amorphous / crystalline resistance ratio, which will affect The on / off ratio of the device; N-Sb-Te is less stable in high temperature practical applications

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