Thin-film device based on GeSbTe phase-change material

Abstract

The invention discloses a thin-film device based on a GeSbTe phase-change material. The thin-film device comprises a substrate layer, a lower electrode layer, a first GeSbTe material layer, a molybdenum disulfide layer, a second GeSbTe material layer, a graphene layer, an upper electrode layer and a protective layer, wherein the lower electrode layer, the first GeSbTe material layer, the molybdenum disulfide layer, the second GeSbTe material layer, the graphene layer, the upper electrode layer and the protective layer are sedimented and laminated on the substrate layer in sequence; the first GeSbTe material layer is an ion-doped GeSbTe phase-change material layer; and the second GeSbTe material layer is a pure-phase GeSbTe phase-change material. The thin-film device based on the GeSbTe phase-change material disclosed by the invention has the characteristics of high heat stability, good consistency, high phase-change speed and long service life.

Description

technical field [0001] The invention relates to the field of phase change memory, in particular to a laminated phase change thin film device with complementary properties of multilayer materials. Background technique [0002] Phase-change memory (PRAM), as a non-volatile storage technology, has greater advantages in size reduction compared with FLASH technology. It not only has the characteristics of fast read and write speed (ns level), high cycle times (>1012), low power consumption, etc., but also is compatible with the existing CMOS process, the technical implementation difficulty and industrial cost are low, and it can realize Multi-bit storage. In addition, PRAM storage technology has strong shock resistance and radiation resistance, and has extremely important application prospects in the aerospace field. These characteristics of PRAM are considered to be the most likely to replace flash memory and become a new generation of non-volatile memory for general use. ...

AI Technical Summary

Problems solved by technology

However, the poor thermal stability caused by the low crystallization temperature and poor data retention of Ge-Sb-Te materials has been restricting its further development in special fields

In practical applications, GeSbTe storage materials have the following disadvantages: such as a large density change during phase transition, and the crystallization speed is not good, generally a few hundred ns, which affects the erasing speed and device reliability; for example, due to the low crystallization temperature (about 150°C), the data of PRAM memory cells using traditional Ge2Sb2Te5 materials as storage media can only be stored for 10 years at 70-110°C, and the data storage life at high temperatures is short and needs to be improved

[0006] However, regardless of whether TiN is used to form an alloy or Zn doped, although the thermal stability of the GST material can be improved, the alloying of TiN and the GST material is still a Zn-doped GST material, and TiN and Zn enter the lattice of the GST material. Uncontrollability, resulting in the poor quality consistency of the prepared GST material. When used as a storage material, local data abnormalities will occur during long-term reading and writing, which directly affects its popularization and application.

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