Using scanning tunneling microscopy (STM), we investigate oxide-induced growth pits in Si thin films deposited by molecular beam epitaxy. In the transition temperature range from 2D adatom islanding to step-flow growth, systematic controlled air leaks into the growth chamber induce pits in the growth surface. We show that pits are also correlated with oxygen-contaminated flux from Si sublimation sources. From a thermodynamic standpoint, multilayer growth pits are unexpected in relaxed homoepitaxial growth, whereas oxidation is a known cause for step-pinning, roughening, and faceting on elemental surfaces, both with and without growth flux. Not surprisingly, pits are thermodynamically metastable and heal by annealing to recover a smooth periodic step arrangement. STM reveals new details about the pits' atomistic origins and growth dynamics. Here, we give a model for heterogeneous nucleation of pits by preferential adsorption of Å-sized oxide nuclei at intrinsic growth antiphase boundaries, and subsequent step pinning and bunching around the nuclei.
Yitamben, Esmeralda, et al. "Heterogeneous nucleation of pits via step pinning during Si(100) homoepitaxy." New Journal of Physics, vol. 19, no. 11, Nov. 2017. https://doi.org/10.1088/1367-2630/aa9397
Yitamben, Esmeralda, Butera, Robert E., Swartzentruber, Brian S., Simonson, Robert J., Misra, Shashank, Carroll, Malcolm S., & Bussmann, Ezra (2017). Heterogeneous nucleation of pits via step pinning during Si(100) homoepitaxy. New Journal of Physics, 19(11). https://doi.org/10.1088/1367-2630/aa9397
Yitamben, Esmeralda, Butera, Robert E., Swartzentruber, Brian S., et al., "Heterogeneous nucleation of pits via step pinning during Si(100) homoepitaxy," New Journal of Physics 19, no. 11 (2017), https://doi.org/10.1088/1367-2630/aa9397
@article{osti_1406367,
author = {Yitamben, Esmeralda and Butera, Robert E. and Swartzentruber, Brian S. and Simonson, Robert J. and Misra, Shashank and Carroll, Malcolm S. and Bussmann, Ezra},
title = {Heterogeneous nucleation of pits via step pinning during Si(100) homoepitaxy},
annote = {Using scanning tunneling microscopy (STM), we investigate oxide-induced growth pits in Si thin films deposited by molecular beam epitaxy. In the transition temperature range from 2D adatom islanding to step-flow growth, systematic controlled air leaks into the growth chamber induce pits in the growth surface. We show that pits are also correlated with oxygen-contaminated flux from Si sublimation sources. From a thermodynamic standpoint, multilayer growth pits are unexpected in relaxed homoepitaxial growth, whereas oxidation is a known cause for step-pinning, roughening, and faceting on elemental surfaces, both with and without growth flux. Not surprisingly, pits are thermodynamically metastable and heal by annealing to recover a smooth periodic step arrangement. STM reveals new details about the pits' atomistic origins and growth dynamics. Here, we give a model for heterogeneous nucleation of pits by preferential adsorption of Å-sized oxide nuclei at intrinsic growth antiphase boundaries, and subsequent step pinning and bunching around the nuclei.},
doi = {10.1088/1367-2630/aa9397},
url = {https://www.osti.gov/biblio/1406367},
journal = {New Journal of Physics},
issn = {ISSN 1367-2630},
number = {11},
volume = {19},
place = {United States},
publisher = {IOP Publishing},
year = {2017},
month = {11}}