Germanium Quantum-Dot Single-Hole Transistors with Self-organized Tunnel Barriers and Self-aligned Electrodes Using Ingenious Sidewall Spacer and Oxidation Techniques

作者：Rong-Cun Pan, I-Hsiang Wang, Chi-Cheng Lai, T. George, Horng‐Chih Lin, Pei-Wen Li · 发表于：2022 6th IEEE Electron Devices Technology & Manufacturing Conference (EDTM) · 年份：2022 · DOI：10.1109/edtm53872.2022.9798091 · 被引用次数：2 · 研究领域：Semiconductor materials and devices、Semiconductor Quantum Structures and Devices、Nanowire Synthesis and Applications

We report the formation of Ge quantum dots (QDs) with self-organized tunnel barriers and self-aligned electrodes, using a coordinated combination of lithographic patterning and self-assembled growth. The core experimental design is based on the thermal oxidation of poly-SiGe spacer islands located at the included-angle location of Si3N4/Si-trenches with specially designed fanout structures. By suitably adjusting the process times for conformal deposition, direct etch back and thermal oxidation of poly-SiGe, Ge QDs and their tunnel barriers with good tunability in sizes and widths were controllably achieved. Ge QDs are electrically addressable via self-aligned Si electrodes, offering an effective building block for the implementation of single-electron devices.