Alloying during local droplet etching of AlGaAs surfaces with aluminium
Alloying during local droplet etching of AlGaAs surfaces with aluminium
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DOI：
10.1063/1.5053464
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发表时间：
2019-01
影响因子：
3.2
通讯作者：
M. Zocher;C. Heyn;W. Hansen
中科院分区：
文献类型：
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作者：
M. Zocher;C. Heyn;W. Hansen
局部液滴蚀刻（LDE）在AlGaAs表面钻取自组装纳米孔，是制造多功能量子结构（如量子点、环和分子）的强大技术。通常，如果使用Al作为蚀刻材料，则在温度T = 600 - 680 ° C下执行LDE。现在，原子力显微镜确定，Al-LDE钻纳米孔也在非常低的温度下，T = 360 ° C，这是300 ° C以下的熔点散装铝。几种可能的蚀刻机制，如熔点下降，固态蚀刻，和合金化进行了讨论。使用HF的选择性湿化学蚀刻实验表明与来自衬底的Ga的显著合金化，并且因此形成用于蚀刻的Al-Ga液滴。对于Al-Ga液滴内的Al含量的x ≤ 50%的上限由HF酸的选择性指示。该值与基于测量的液滴和孔体积的x = 0.42的估计一致。与T…
Local droplet etching (LDE) drills self-assembled nanoholes into AlGaAs surfaces and represents a powerful technique for the fabrication of versatile quantum structures like quantum dots, rings, and molecules. Usually, LDE is performed at temperatures T = 600 − 680 ° C if Al is used as the etching material. Now, atomic force microscopy establishes that Al-LDE drills nanoholes also at very low temperatures down to T = 360 ° C which is 300 ° C below the melting point of bulk Al. Several possible etching mechanisms like a melting-point depression, solid-state etching, and alloying are discussed. Selective wet-chemical etching experiments using HF indicate significant alloying with Ga from the substrate, and thus the formation of Al-Ga droplets for etching. The upper limit of x ≤ 50 % for the Al content inside the Al-Ga droplets is indicated by the selectivity of the HF acid. This value is in agreement with an estimation of x = 0.42, which is based on the measured droplet and hole volumes. A comparison with t...