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Tunable zero-field magnetoresistance responses in Si transistors: Origins and applications



Stephen Moxim, Nicholas Harmon, Kenneth Myers, James P Ashton, Elias Frantz, Michael Flatté, Patrick Lenahan, Jason Ryan


The near-zero-field magnetoresistance (NZFMR) response has proven to be a useful tool for studying atomic-scale, paramagnetic defects that are relevant to the reliability of semiconductor devices. The measurement is simple to make and, in some cases, simple to interpret. In other cases, more sophisticated modeling based on the stochastic Liouville equation (SLE) is needed to access valuable information from NZFMR results. It has been shown that hyperfine and dipolar coupling interactions at atomic-scale defects affect the NZFMR lineshape, but experimental parameters related to the detection method of NZFMR can also affect the nature of the response. Here, we demonstrate four distinct NZFMR detection methods in Si MOSFETs which all access identical Si/SiO2 interface defects. In all four cases, we show that the lineshape of the response is tunable based on experimental parameters alone. We verify that time constants connected to physical carrier capture rates at the defect sites lead to these NZFMR lineshape changes by using SLE-based modeling. The results demonstrate a method to extract some atomic-scale information about the defect for the purposes of defect identification. They also have broader applications to the continued development of ultra-sensitive magnetometers based on NZFMR in semiconductors. Additionally, the NZFMR effect in common Si-based devices may provide an inexpensive and accessible platform that mimics similar radical pair mechanisms that have become increasingly important in various biology fields.
Journal of Applied Physics


Magnetoresistance, defects in semiconductors, magnetoresistance, quantum biology


Moxim, S. , Harmon, N. , Myers, K. , Ashton, J. , Frantz, E. , Flatté, M. , Lenahan, P. and Ryan, J. (2024), Tunable zero-field magnetoresistance responses in Si transistors: Origins and applications, Journal of Applied Physics, [online],, (Accessed May 26, 2024)


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Created April 16, 2024, Updated April 26, 2024