Electron-electron interactions in highly degenerately doped embedded Si:P delta layers in silicon produced by variable PH3 dosing
Abstract
Key to producing quantum computing devices based on the atomistic placement of dopants in Si by STM lithography is the formation of embedded highly doped Si:P delta layers (δ-layers). This study investigates the transport behavior and the electron-electron interaction (EEI) physics in the highly doped regions of embedded Si:P-based devices by means of self-consistent magnetotransport (MT) measurements. In earlier work, we demonstrated that a careful MT study at low T, along with analysis of the weak localization (WL) signal, allows us to extract parameters associated with the electronic transport that offer a meaningful quantitative characterization of δ-layer quality and dopant diffusion. We build on this work by examining EEI behaviors in a set of samples with embedded Si:P delta layers produced with different PH3 exposure procedures prior to Si encapsulation. We show that the charge carriers behave as 2DEGs in embedded Si:P δ-layers in samples grown with a locking layer (LL) to bolster confinement of the dopants, while samples grown without a LL demonstrate several signatures of transport and EEI in a 3D system. The impact between δ-layer confinement and EEI on screening lengths affects both electrostatic gating of and tunneling transport through Si:P single atom transistors.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..MARP11012H