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Subject of the Master's internship

Hybrid simulation of III-V & II-VI semiconductor surfaces


Possible extension as a PhD.
Published on 15 October 2020
Summary
The description of surface reconstruction is a key in semiconductor science. The goal of this internship is to adapt an hybrid simulation scheme [1] mixing density functional theory (DFT) and force field descriptions in order to allow accurate and tractable simulation of defect states at such surfaces. Targeted systems include metallic atoms that are envisioned as a possible qbits for future quantum computing [2] as well as interfaces with a 2D material resulting from the recently proposed remote epitaxy process [3].

Full description of the subject
Surface science has been renewed in the last decade due to the raise of 2D materials and nanosciences in general. Although they have been studied from many decades, an accurate simulation of the surface physics remains a difficult task for some systems of interest. This comes from the need to reproduce the intrinsic electronic effect at the surface together with long range elastic deformations in the bulk of the film. In order to simulate such system an hybrid simulation scheme mixing DFT and force field description can be used. We recently used such technique to analyse the key ingredient in the co-integration of GaAs on silicon wafer [1].

Deformation field induced by a line of missing dimers on the silicon surface.

In this paper, the surface physics derived from the silicon itself, for which the QM/MM method have been initially implemented in the BigDFT package. The goal of the master thesis is to enhance the catalog of available force fields for III-V and II-VI. The developed method will be applied on a system connected to quantum computing material for which STM topographies are available from our experimental partners. A PhD will be opened to address related interfaces grown at Leti for various applications.

Keywords
DFT, force fields, III-V compounds

Possible extension as a PhD

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