The nuclear spins of low-density implanted Ga atoms in Ge are interesting candidates for solid state-based qubits. To date, activation studies of implanted Ga in Ge have focused on high densities. Here, we extend activation studies into the low-density regime. We use spreading resistance profiling and secondary ion mass spectrometry to derive electrical activation of Ga ions implanted into Ge as a function of the rapid thermal anneal temperature and implant density. We show that for our implant conditions, the activation is best for anneal temperatures between 400 and 650 °C with a maximum activation of 69% at the highest fluence. Below 400 °C, remaining implant damage results in defects that act as superfluous carriers, and above 650 °C, surface roughening and loss of Ga ions are observed. The activation increased monotonically from 10% to 69% as the implant fluence increased from 6×1010 to 6×1012 cm−2. The results provide thermal anneal conditions to be used for initial studies of using low-density Ga atoms in Ge as nuclear spin qubits.
Foster, Natalie D., et al. "Thermal activation of low-density Ga implanted in Ge." Applied Physics Letters, vol. 120, no. 20, May. 2022. https://doi.org/10.1063/5.0094900
Foster, Natalie D., Miller, Andrew J., Hutchins-Delgado, Troy A., Smyth, Christopher M., Wanke, Michael C., Lu, Tzu-Ming, & Luhman, Dwight R. (2022). Thermal activation of low-density Ga implanted in Ge. Applied Physics Letters, 120(20). https://doi.org/10.1063/5.0094900
Foster, Natalie D., Miller, Andrew J., Hutchins-Delgado, Troy A., et al., "Thermal activation of low-density Ga implanted in Ge," Applied Physics Letters 120, no. 20 (2022), https://doi.org/10.1063/5.0094900
@article{osti_1868401,
author = {Foster, Natalie D. and Miller, Andrew J. and Hutchins-Delgado, Troy A. and Smyth, Christopher M. and Wanke, Michael C. and Lu, Tzu-Ming and Luhman, Dwight R.},
title = {Thermal activation of low-density Ga implanted in Ge},
annote = {The nuclear spins of low-density implanted Ga atoms in Ge are interesting candidates for solid state-based qubits. To date, activation studies of implanted Ga in Ge have focused on high densities. Here, we extend activation studies into the low-density regime. We use spreading resistance profiling and secondary ion mass spectrometry to derive electrical activation of Ga ions implanted into Ge as a function of the rapid thermal anneal temperature and implant density. We show that for our implant conditions, the activation is best for anneal temperatures between 400 and 650 °C with a maximum activation of 69% at the highest fluence. Below 400 °C, remaining implant damage results in defects that act as superfluous carriers, and above 650 °C, surface roughening and loss of Ga ions are observed. The activation increased monotonically from 10% to 69% as the implant fluence increased from 6×1010 to 6×1012 cm−2. The results provide thermal anneal conditions to be used for initial studies of using low-density Ga atoms in Ge as nuclear spin qubits.},
doi = {10.1063/5.0094900},
url = {https://www.osti.gov/biblio/1868401},
journal = {Applied Physics Letters},
issn = {ISSN 0003-6951},
number = {20},
volume = {120},
place = {United States},
publisher = {American Institute of Physics},
year = {2022},
month = {05}}
Ziegler, James F.; Ziegler, M. D.; Biersack, J. P.
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, Vol. 268, Issue 11-12https://doi.org/10.1016/j.nimb.2010.02.091