Measurement of phosphorus segregation in silicon at the atomic-scale using STM
Abstract
In order to fabricate precise atomic-scale devices in silicon using a combination of scanning tunnelling microscopy (STM) and molecular beam epitaxy it is necessary to minimize the segregation/diffusion of dopant atoms during silicon encapsulation. We characterize the surface segregation/diffusion of phosphorus atoms from a -doped layer in silicon after encapsulation at 250C and room temperature using secondary ion mass spectrometry (SIMS), Auger electron spectroscopy (AES), and STM. We show that the surface phosphorus density can be reduced to a few percent of the initial -doped density if the phosphorus atoms are encapsulated with 5 or 10 monolayers of epitaxial silicon at room temperature. We highlight the limitations of SIMS and AES to determine phosphorus segregation at the atomic-scale and the advantage of using STM directly.
Keywords
Cite
@article{arxiv.cond-mat/0307495,
title = {Measurement of phosphorus segregation in silicon at the atomic-scale using STM},
author = {Lars Oberbeck and Neil J. Curson and Toby Hallam and Michelle Y. Simmons and Robert G. Clark and Gerhard Bilger},
journal= {arXiv preprint arXiv:cond-mat/0307495},
year = {2009}
}