Capture processes at double donors in silicon

The hole-capture processes at isolated double donors in chalcogen-doped silicon have been investigated. Different steady-state and transient-capacitance techniques were used. It is shown that the capture process at neutral centers is governed by an Auger-type capture process at a He-like center. The hole-capture cross sections for neutral centers are almost temperature independent and have values of about 10^-16 cm². The processes for hole capture at singly ionized centers are best described as a multiphonon emission and/or a radiative process. At low temperatures the cross sections are about 10^-24--10^-22 cm².