Synthesis and characterization of P δ-layer in SiO₂ by monolayer doping

Achieving the required control of dopant distribution and selectivity for nanostructured semiconducting building block is a key issue for a large variety of applications. A promising strategy is monolayer doping (MLD), which consists in the creation of a well-ordered monolayer of dopant-containing molecules bonded to the surface of the substrate. In this work, we synthesize a P δ−layer embedded in a SiO₂ matrix by MLD. Using a multi-technique approach based on time of flight secondary ion mass spectrometry (ToF-SIMS) and Rutherford backscattering spectrometry (RBS) analyses, we characterize the tuning of P dose as a function of the processing time and temperature. We found the proper conditions for a full grafting of the molecules, reaching a maximal dose of 8.3 × 10¹⁴ atoms/cm². Moreover, using 1D rate equation model, we model P diffusion in SiO₂ after annealing and we extract a P diffusivity in SiO₂ of 1.5 × 10¹⁷ cm² s⁻¹. (paper)