Hydrogen plasma-enhanced thermal donor formation in n-type oxygen-doped high-resistivity float-zone silicon

The impact of plasma hydrogenation on the subsequent formation of thermal donors at 450 degreesC in n-type oxygen-doped high-resistivity float-zone silicon is investigated by a combination of electrical and spectroscopic techniques. It is shown that the increase of the doping concentration can be explained by the creation of two sets of donors. The first one is the classical double oxygen thermal donors (OTDs), which are introduced with a nearly uniform concentration profile across the sample thickness, while the second type of donors is shallower and most likely hydrogen related. The latter show a pronounced concentration profile towards the surface and they form and disappear at a much faster rate than the OTDs at 450 degreesC. (C) 2002 American Institute of Physics.