Dopant Precursor Adsorption into Single-Dimer Windows: Towards Guided Self-Assembly of Dopant Arrays on Si(100)

Abstract

Atomically precise dopant arrays in Si are being pursued for solid-state quantum computing applications. We propose a guided self-assembly process to produce atomically precise arrays of single dopant atoms in lieu of lithographic patterning. We leverage the self-assembled c(4x2) structure formed on Br-and I-Si(100) and investigate molecular precursor adsorption into the generated array of single-dimer window (SDW) adsorption sites with density functional theory (DFT). The adsorption of several technologically relevant dopant precursors (PH 3 , BCl 3 , AlCl 3 , GaCl 3 ) into SDWs formed with various resists (H, Cl, Br, I) are explored to identify the effects of steric interactions. PH 3 adsorbed without barrier on all resists studied, while BCl 3 exhibited the largest adsorption barrier, 0.34 eV, with an I resist. Dense arrays of AlCl 3 were found to form within experimentally realizable conditions demonstrating the potential for the proposed use of guided self-assembly for atomically precise fabrication of dopant-based devices.