Abstract
We study the coupling of P dangling bond defects at the Si/SiO2 interface and 31P donors in an epitaxial layer directly underneath using electrically detected double electron–electron resonance (EDDEER). An exponential decay of the EDDEER signal is observed, which is attributed to a broad distribution of exchange coupling strengths J/2π from 25 kHz to 3 MHz. Comparison of the experimental data with a numerical simulation of the exchange coupling shows that this range of coupling strengths corresponds to 31P–P
distances ranging from 14 nm to 20 nm.
Acknowledgements
The work was supported by DFG (Grant No. SFB 631, C3 and Grant No. SPP 1601, Br 1585/8-1) and BMBF (Grant No. EPR Solar).