Phase dependence of Schottky barrier heights for Ge-Sb-Te and related phase-change materials

被引：0

作者：

Zhang, Zhaofu ^{[1
]}

Guo, Yuzheng ^{[2
]}

Robertson, John ^{[1
]}

机构：

[1] Department of Engineering, University of Cambridge, Cambridge,CB2 1PZ, United Kingdom

[2] College of Engineering, Swansea University, Swansea,SA1 8EN, United Kingdom

来源：

Journal of Applied Physics | 2020年 / 127卷 / 15期

关键词：

Tin compounds;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

The large difference of dielectric functions between the amorphous and crystalline phases of Ge-Sb-Te based phase-change materials (PCMs) used in memory storage devices also affects their Schottky barrier heights (SBHs) and thus their electrical device properties. Here, the SBHs of each phase of Ge2Sb2Te5, GeTe, GeSe, and SnTe are found by density functional supercell calculations. The Fermi level pinning factor S calculated for the crystalline phases (with a larger dielectric constant) is smaller than their amorphous phases, agreeing well with the empirical relationship linking SBH to a dielectric constant. The relatively large dielectric constant of crystalline PCMs arises from their resonant bonding (metavalent bonding), but their pinning factor is not always as small as empirically expected. The results are useful for optimizing the design of metal contacts for Ge-Sb-Te type phase-change memory devices. © 2020 Author(s).

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