Keywords
Abstract
The effect of rapid thermal annealing in H2 atmosphere on the ohmic properties of contacts on the basis of two-layered transition metals (e.g. Ti, Ni, Pd and Cr) and Au compositions on р+-Si has been studied. It has been shown for the example of two-layered Ti/Au compositions that rapid thermal annealing in H2 atmosphere at 340 °C for 20 s provides for an ohmic contact with lowest specific resistivity due to the formation of silicides at the Si/Me interface (Me = Ti, Ni, Pd and Cr). The applicability of the process in silicon diode technology for reducing the series resistance and increasing the device yield has been confirmed for small contact area commercial p+–n clamping diodes. Furthermore, the effect of rapid thermal annealing in H2 atmosphere on the level of reverse dark currents in highly ohmic p-Si photodiode has been studied. The results for the commercial p–i–n silicon multi-pad photocells suggest an improvement of the dark currents of the photosensitive pads and the guard ring after rapid thermal annealing in H2 atmosphere at 450 °C for 5 s and an increase in the device yield. This can be attributed to the hydrogen saturation of the dangling silicon bonds, providing for a decrease in the density of the surface states and stabilization of the charge properties at the SiO2/p-Si interface. The applicability of rapid thermal annealing in H2 atmosphere for dark current reduction in highly ohmic p-Si photodiode technology has been confirmed.
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