Electrically-detected magnetic resonance in accumulation-layer MOSFETs

Spin-dependent transport, originating from neutral-impurity scattering, in silicon accumulation-layer MOSFETs was reported more than a decade ago in an electron-spin resonance (ESR) cavity setup [1]. There, current measurements on the MOSFET showed ESR features with a hyperfine (HF) splitting of 42 G, indicative of electrons whose wavefunctions overlap with phosphorous nuclei in the silicon crystal. Here, we report the observation of electrically-detected magnetic resonance (EDMR) in phosphorous-doped silicon MOSFETs without the constraint of a cavity and down to the mK-regime in a dilution refrigerator with a superconducting magnet. Instead, the ESR-field is generated by an on-chip shorted coplanar stripline (CPS), allowing broadband operation. Continuous-wave EDMR was achieved up to 30 GHz. The EDMR spectra show (i) the two hyperfine-split (42 G) ESR lines and (ii) an EDMR signal that is centered between the hyperfine lines, associated with the `free electron' ESR response. [1] R. Ghosh and W. Silsbee, Phys. Lett. 85, 439 (1992).