  Spin-dependent transport processes in thin near-surface doping regions
created by low energy ion implantation of arsenic in silicon are detected by
two methods, spin-dependent recombination (SDR) using microwave
photoconductivity and electrically detected magnetic resonance (EDMR)
monitoring the DC current through the sample. The high sensitivity of these
techniques allows the observation of the magnetic resonance in particular of As
in weak magnetic fields and at low resonance frequencies (40-1200 MHz), where
high-field-forbidden transitions between the magnetic substates can be observed
due to the mixing of electron and nuclear spin states. Several
implantation-induced defects are present in the samples studied and act as spin
readout partner. We explicitly demonstrate this by electrically detected
electron double resonance experiments and identify a pair recombination of
close pairs formed by As donors and oxygen-vacancy centers in an excited
triplet state (SL1) as the dominant spin-dependent process in As-implanted
Czochralski-grown Si.
