| AVS 66th International Symposium & Exhibition | |
| 2D Materials | Monday Sessions |
| Session 2D+AP+EM+MI+NS+PS+TF-MoA |
| Session: | 2D Materials Growth and Fabrication |
| Presenter: | Aparna Pilli, University of North Texas |
| Authors: | A. Pilli, University of North Texas J. Jones, University of North Texas J.A. Kelber, University of North Texas A. LaVoie, Lam Research Corporation F. Pasquale, Lam Research Corporation |
| Correspondent: | Click to Email |
The deposition of boron oxide (B2O3) films on Si and SiO2 substrates by atomic layer deposition (ALD) is of growing interest in microelectronics for shallow doping of high aspect ratio transistor structures. B2O3, however, forms volatile boric acid (H3BO3) upon ambient exposure, requiring a passivation barrier, for which BN was investigated as a possible candidate. Here, we demonstrate, deposition of BN by sequential BCl /NH reactions at 600 K on two different oxidized boron substrates: (a) B O deposited using BCl /H O ALD on Si at 300 K (“B O /Si”); and (b) a boron-silicon oxide formed by sequential BCl /O reactions at 650 K on SiO followed by annealing to 1000 K (“B-Si-oxide”). X-ray photoelectron spectroscopy (XPS) data demonstrate layer-by-layer growth of BN on B2O3/Si with an average growth rate of ~1.4 Å/cycle, accompanied by some B2O3 removal during the first BN cycle. In contrast, continuous BN growth was observed on B-Si-oxide without any reaction with the substrate. XPS data also indicate that the oxide/nitride heterostructures are stable upon annealing in ultrahigh vacuum to >1000 K. XPS data, after the exposure of these heterostructures to ambient, indicate a small amount of BN oxidation at the surface NH species, with no observable hydroxylation of the underlying oxide films. These results demonstrate that BN films, as thin as 13 Å, are potential candidates for passivating boron oxide films prepared for shallow doping applications.