Reducing disorder in Ge quantum wells by using thick SiGe barriers

IF 3.5 2区物理与天体物理 Q2 PHYSICS, APPLIED

Applied Physics Letters Pub Date : 2024-11-26 DOI:10.1063/5.0242746

Davide Costa, Lucas E. A. Stehouwer, Yi Huang, Sara Martí-Sánchez, Davide Degli Esposti, Jordi Arbiol, Giordano Scappucci

引用次数: 0

Abstract

We investigate the disorder properties of two-dimensional hole gases in Ge/SiGe heterostructures grown on Ge wafers, using thick SiGe barriers to mitigate the influence of the semiconductor–dielectric interface. Across several heterostructure field effect transistors, we measure an average maximum mobility of (4.4±0.2)×106 cm2/Vs at a saturation density of (1.72±0.03)×1011 cm−2, corresponding to a long mean free path of (30±1)μm. The highest measured mobility is 4.68×106 cm2/Vs. We identify uniform background impurities and interface roughness as the dominant scattering mechanisms limiting mobility in a representative device, and we evaluate a percolation-induced critical density of (4.5±0.1)×109 cm−2. This low-disorder heterostructure, according to simulations, may support the electrostatic confinement of holes in gate-defined quantum dots.

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利用厚硅锗势垒减少 Ge 量子阱中的无序状态

我们研究了在 Ge 硅片上生长的 Ge/SiGe 异质结构中二维空穴气体的无序特性，使用厚 SiGe 势垒来减轻半导体-介电界面的影响。在几个异质结构场效应晶体管中，我们测得饱和密度为 (1.72±0.03)×1011 cm-2 时的平均最大迁移率为 (4.4±0.2)×106 cm2/Vs，对应的平均自由长路径为 (30±1)μm。测得的最高迁移率为 4.68×106 cm2/Vs。我们确定均匀背景杂质和界面粗糙度是限制代表性器件迁移率的主要散射机制，并评估出渗滤诱导的临界密度为 (4.5±0.1)×109 cm-2。模拟结果表明，这种低无序异质结构可以支持栅极量子点中空穴的静电约束。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Applied Physics Letters 物理-物理：应用

CiteScore

6.40

自引率

10.00%

发文量

1821

审稿时长

1.6 months

期刊介绍： Applied Physics Letters (APL) features concise, up-to-date reports on significant new findings in applied physics. Emphasizing rapid dissemination of key data and new physical insights, APL offers prompt publication of new experimental and theoretical papers reporting applications of physics phenomena to all branches of science, engineering, and modern technology. In addition to regular articles, the journal also publishes invited Fast Track, Perspectives, and in-depth Editorials which report on cutting-edge areas in applied physics. APL Perspectives are forward-looking invited letters which highlight recent developments or discoveries. Emphasis is placed on very recent developments, potentially disruptive technologies, open questions and possible solutions. They also include a mini-roadmap detailing where the community should direct efforts in order for the phenomena to be viable for application and the challenges associated with meeting that performance threshold. Perspectives are characterized by personal viewpoints and opinions of recognized experts in the field. Fast Track articles are invited original research articles that report results that are particularly novel and important or provide a significant advancement in an emerging field. Because of the urgency and scientific importance of the work, the peer review process is accelerated. If, during the review process, it becomes apparent that the paper does not meet the Fast Track criterion, it is returned to a normal track.