Spin-Dependent Processes At The Crystalline Si-Sio2 Interface At High Magnetic Fields

An experimental study on the nature of spin-dependent excess charge-carrier transitions at the interface between (111)-oriented phosphorous-doped ([P]approximate to 10(15) cm(-3)) crystalline silicon and silicon dioxide at high magnetic field (B-0 approximate to 8.5 T) is presented. Electrically detected magnetic-resonance (EDMR) spectra of the hyperfine split P-31 donor-electron transitions and paramagnetic interface defects were conducted at temperatures in the range of 3 K <= T <= 12 K. The results at these previously unattained (for EDMR) magnetic-field strengths reveal the dominance of spin-dependent processes that differ from the previously well investigated recombination between the P-31 donor and the P-b state, which dominates at low magnetic fields. While magnetic resonant current responses due to P-31 and P-b states are still present, they do not correlate and only the P-b contribution can be associated with an interface process due to spin-dependent tunneling between energetically and physically adjacent P-b states. This work provides an experimental demonstration of spin-dependent tunneling between physically adjacent and identical electronic states as proposed by Kane [Nature (London) 393, 133 (1998)] for readout of donor qubits.