Hole in one: Pathways to deterministic single-acceptor incorporation in Si(100)-2$\times$1

TL;DR

This study models the incorporation rates of different acceptor precursors in silicon to identify conditions for deterministic single-acceptor placement, crucial for scalable atomic-precision semiconductor fabrication.

Contribution

It develops an atomistic model to predict and compare the incorporation efficiency of various acceptor precursors, guiding deterministic doping strategies.

Findings

Boron trichloride can achieve deterministic incorporation with modest heating.

Aluminum trichloride can do so at room temperature.

Diborane is unlikely to achieve deterministic incorporation.

Abstract

Stochastic incorporation kinetics can be a limiting factor in the scalability of semiconductor fabrication technologies using atomic-precision techniques. While these technologies have recently been extended from donors to acceptors, the extent to which kinetics will impact single-acceptor incorporation has yet to be assessed. We develop and apply an atomistic model for the single-acceptor incorporation rates of several recently demonstrated precursor molecules: diborane (B$_2$H$_6$), boron trichloride (BCl$_3$), and aluminum trichloride in both monomer (AlCl$_3$) and dimer forms (Al$_2$Cl$_6$), to identify the acceptor precursor and dosing conditions most likely to yield deterministic incorporation. While all three precursors can achieve single-acceptor incorporation, we predict that diborane is unlikely to achieve deterministic incorporation, boron trichloride can achieve deterministic incorporation with modest heating (50 $^{\circ}$C), and aluminum trichloride can achieve deterministic incorporation at room temperature. We conclude that both boron and aluminum trichloride are promising precursors for atomic-precision single-acceptor applications, with the potential to enable the reliable production of large arrays of single-atom quantum devices.