The treatment of an Ar + H2 plasma generated by a low-frequency inductively coupled plasma system at 500C introduces an n-type region (of average electron concentration ~1015/cm3) on a Czochralski p-type substrate, forming a deep p–n junction. Examination by an electron microscope showed that the plasma treatment produced uniform nanocones on the surface and some defects, such as dislocations and platelets, in the subsurface. All these observed results were hydrogen-related. The conductivity type conversion was due to the formation of hydrogen-enhanced oxygen-related thermal donors as well as hydrogen-incorporated shallow thermal donors. The oxygen-related thermal donor-related signals were directly observed in the infrared absorption spectra. Both donors were annihilated after annealing at 550C for 10 min, resulting in conductivity recovery from n-type to original p-type. The electrical properties of the as-formed junction were investigated using current versus voltage, capacitance versus voltage and Hall effect measurements. On this basis, the junction depth, carrier profile and hydrogen diffusion behaviour were studied. Moreover, a clear photovoltaic effect of the junction was observed through the Suns-Voc and illuminated current versus voltage tests.

On Conductivity Type Conversion of p-Type Silicon Exposed to a Low-Frequency Inductively Coupled Plasma of Ar+H2. H.P.Zhou, L.X.Xu, S.Xu, S.Y.Huang, D.Y.Wei, S.Q.Xiao, W.S.Yan, M.Xu: Journal of Physics D, 2010, 43[50], 505402