Probing the Atomic Arrangement of Subsurface Dopants in a Silicon Quantum Device Platform
Røst, Håkon; Tosi, Ezequiel; Strand, Frode Sneve; Åsland, Anna Cecilie; Lacovig, Paolo; Lizzit, Silvano; Wells, Justin William
Peer reviewed, Journal article
Published version
Permanent lenke
https://hdl.handle.net/11250/3110030Utgivelsesdato
2023Metadata
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- Institutt for fysikk [2772]
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Originalversjon
ACS Applied Materials & Interfaces. 2023, 15 (18), 22637-22643. 10.1021/acsami.2c23011Sammendrag
High-density structures of subsurface phosphorus dopants in silicon continue to garner interest as a silicon-based quantum computer platform; however, a much-needed confirmation of their dopant arrangement has been lacking. In this work, we take advantage of the chemical specificity of X-ray photoelectron diffraction to obtain the precise structural configuration of P dopants in subsurface Si:P δ-layers. The growth of δ-layer systems with different levels of doping is carefully studied and verified using X-ray photoelectron spectroscopy and low-energy electron diffraction. Subsequent diffraction measurements reveal that in all cases, the subsurface dopants primarily substitute with Si atoms from the host material. Furthermore, no signs of carrier-inhibiting P–P dimerization can be observed. Our observations not only settle a nearly decade-long debate about the dopant arrangement but also demonstrate how X-ray photoelectron diffraction is surprisingly well suited for studying subsurface dopant structure. This work thus provides valuable input for an updated understanding of the behavior of Si:P δ-layers and the modeling of their derived quantum devices.