Scanning electron microscopy observation of in-device InAs/AlAs quantum dots by selective etching of capping layers

Jie Sun, Dayong Zhou, Ruoyuan Li, Chang Zhao, Xiaoling Ye, Bo Xu, Yonghai Chen, Zhanguo Wang

Research output: Contribution to journalArticlepeer-review

Abstract

Self-assembled InAs/AlAs quantum dots embedded in a resonant tunneling diode device structure are grown by molecular beam epitaxy. Through the selective etching in a C6H8O7 center dot H2O-K3C6H5O7 center dot H2O-H2O2 buffer solution, 310 nm GaAs capping layers are removed and the InAs/AlAs quantum dots are observed by field-emission scanning electron microscopy. It is shown that as-fabricated quantum dots have a diameter of several tens of nanometers and a density of 10(10) cm(-2) order. The images taken by this means are comparable or slightly better than those of transmission electron microscopy. The undercut of the InAs/AlAs layer near the edges of mesas is detected and that verifies the reliability of the quantum dot images. The inhomogeneous oxidation of the upper AlAs barrier in H2O2 is also observed. By comparing the morphologies of the mesa edge adjacent regions and the rest areas of the sample, it is concluded that the physicochemical reaction introduced in this letter is diffusion limited.
Original languageEnglish
Pages (from-to)859-866
JournalModern Physics Letters B
Volume21
Issue number14
DOIs
Publication statusPublished - 2007

Subject classification (UKÄ)

  • Condensed Matter Physics

Keywords

  • scanning electron microscopy
  • III-V semiconductors
  • quantum dots
  • selective etching

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