arXiv subjects

Patrick M. Lenahan

Publications and source records attributed to Patrick M. Lenahan.

4 recordsLinked to original sources

arXiv2026

Theory of Electrically Detected Magnetic Resonance of Silicon Vacancy-Related Spin Pairs in Silicon Carbide

We present a quantitative theory for simulating the electrically detected magnetic resonance (EDMR) of silicon vacancy-related spin pairs in silicon carbide using steady-state Lindblad master equations. In our theory, we consider V1a and V2a deep level silicon vacancies near the (0/-) charge state transition level in proximity to a previously identified nitrogen-related complex, the incomplete K-center, due to the hyperfine, spin structure, and Landé g factor of the shallow state. Our theory describes recent room temperature measurements attributed to V1a silicon vacancies, with reasonable extracted parameters for defect spin coherence times and electrical transport rates. At lower temperatures we predict that the shallow level hyperfine structure may be spectrally resolvable. Finally, we predict the EDMR spectrum of V2a silicon vacancy-related spin pairs and predict that two-photon, double quantum transitions of the silicon vacancy's negative charge state can be electrically read-out for enhanced magnetic field sensing.

cond-mat.mtrl-sci↗

arXiv2023

Spin-Dependent Capture Mechanism for Magnetic Field Effects on Interface Recombination Current in Semiconductor Devices

Electrically detected magnetic resonance (EDMR) and near-zero field magnetoresistance (NZFMR) are techniques that probe defect states at dielectric interfaces critical for metal-oxide-semiconductor (MOS) electronic devices such as the Si/SiO$_2$ MOS field effect transistor (MOSFET). A comprehensive theory, adapted from the trap-assisted recombination theory of Shockley, Read, and Hall, is introduced to include the spin-dependent recombination effects that provide the mechanism for magnetic field sensitivity.

cond-mat.mtrl-sci↗

arXiv2020

Near-Zero-Field Spin-Dependent Recombination Current and Electrically Detected Magnetic Resonance from the Si/SiO$_2$ interface

Dielectric interfaces critical for metal-oxide-semiconductor (MOS) electronic devices, such as the Si/SiO$_2$ MOS field effect transistor (MOSFET), possess trap states that can be visualized with electrically-detected spin resonance techniques, however the interpretation of such measurements has been hampered by the lack of a general theory of the phenomena. This article presents such a theory for two electrical spin-resonance techniques, electrically detected magnetic resonance (EDMR) and the recently observed near-zero field magnetoresistance (NZFMR), by generalizing Shockley Read Hall trap-assisted recombination current calculations via stochastic Liouville equations. Spin mixing at this dielectric interface occurs via the hyperfine interaction, which we show can be treated either quantum mechanically or semiclassically, yielding distinctive differences in the current across the interface. By analyzing the bias dependence of NZFMR and EDMR, we find that the recombination in a Si/SiO$_2$ MOSFET is well understood within a semiclassical approach.

cond-mat.mtrl-sci↗

arXiv2020

Extraction of Isotropic Electron-Nuclear Hyperfine Coupling Constants of Paramagnetic Point Defects from Near-Zero Field Magnetoresistance Spectra via Least Squares Fitting to Models Developed from the Stochastic Quantum Liouville Equation

We report on a method by which we can systematically extract spectroscopic information such as isotropic electron-nuclear hyperfine coupling constants from near-zero field magnetoresistance spectra. The method utilizes a least squares fitting of models developed from the stochastic quantum Liouville equation. We applied our fitting algorithm to two distinct material systems: Si/SiO2 MOSFETs, and a-Si:H MIS capacitors. Our fitted results and hyperfine parameters are in reasonable agreement with existing knowledge of the defects present in the systems. Our work indicates that the NZFMR response and fitting of the NZFMR spectrum via models developed from the stochastic quantum Liouville equation could be a relatively simple yet powerful addition to the family of spin-based techniques used to explore the chemical and structural nature of point defects in semiconductor devices and insulators.

cond-mat.mtrl-sci↗