A recently discovered, enhanced Ge diffusion mechanism along the oxidizing interface of Si/SiGe nanostructures has enabled the formation of single-crystal Si nanowires and quantum dots embedded in a defect-free, single-crystal SiGe matrix. Here, we report oxidation studies of Si/SiGe nanofins aimed at gaining a better understanding of this novel diffusion mechanism. Here, a superlattice of alternating Si/Si0.7Ge0.3 layers was grown and patterned into fins. After oxidation of the fins, the rate of Ge diffusion down the Si/SiO2 interface was measured through the analysis of HAADF-STEM images. The activation energy for the diffusion of Ge down the sidewall was found to be 1.1 eV, which is less than one-quarter of the activation energy previously reported for Ge diffusion in bulk Si. Through a combination of experiments and DFT calculations, we propose that the redistribution of Ge occurs by diffusion along the Si/SiO2 interface followed by a reintroduction into substitutional positions in the crystalline Si.
Thornton, Chappel S., et al. "The Diffusion Mechanism of Ge During Oxidation of Si/SiGe Nanofins." ACS Applied Materials and Interfaces, vol. 14, no. 25, Jun. 2022. https://doi.org/10.1021/acsami.2c05470
Thornton, Chappel S., Tuttle, Blair, Turner, Emily, Law, Mark E., Pantelides, Sokrates T., Wang, George T., & Jones, Kevin S. (2022). The Diffusion Mechanism of Ge During Oxidation of Si/SiGe Nanofins. ACS Applied Materials and Interfaces, 14(25). https://doi.org/10.1021/acsami.2c05470
Thornton, Chappel S., Tuttle, Blair, Turner, Emily, et al., "The Diffusion Mechanism of Ge During Oxidation of Si/SiGe Nanofins," ACS Applied Materials and Interfaces 14, no. 25 (2022), https://doi.org/10.1021/acsami.2c05470
@article{osti_1877137,
author = {Thornton, Chappel S. and Tuttle, Blair and Turner, Emily and Law, Mark E. and Pantelides, Sokrates T. and Wang, George T. and Jones, Kevin S.},
title = {The Diffusion Mechanism of Ge During Oxidation of Si/SiGe Nanofins},
annote = {A recently discovered, enhanced Ge diffusion mechanism along the oxidizing interface of Si/SiGe nanostructures has enabled the formation of single-crystal Si nanowires and quantum dots embedded in a defect-free, single-crystal SiGe matrix. Here, we report oxidation studies of Si/SiGe nanofins aimed at gaining a better understanding of this novel diffusion mechanism. Here, a superlattice of alternating Si/Si0.7Ge0.3 layers was grown and patterned into fins. After oxidation of the fins, the rate of Ge diffusion down the Si/SiO2 interface was measured through the analysis of HAADF-STEM images. The activation energy for the diffusion of Ge down the sidewall was found to be 1.1 eV, which is less than one-quarter of the activation energy previously reported for Ge diffusion in bulk Si. Through a combination of experiments and DFT calculations, we propose that the redistribution of Ge occurs by diffusion along the Si/SiO2 interface followed by a reintroduction into substitutional positions in the crystalline Si.},
doi = {10.1021/acsami.2c05470},
url = {https://www.osti.gov/biblio/1877137},
journal = {ACS Applied Materials and Interfaces},
issn = {ISSN 1944-8244},
number = {25},
volume = {14},
place = {United States},
publisher = {American Chemical Society (ACS)},
year = {2022},
month = {06}}