Static high field domains in n-Si

The behaviour of static high field domains in Si is investigated, when there is ndc realized for the <100> crystallographic orientation at temperatures below 50 K. If the parasitic capacities do not influence the measurements there are three groups of samples according to the boundary conditions. In dumb-bell shaped samples where the contact region plays no role at all, the static high field domains are nucleated at the anode independently on the polarity of the voltage applied and in accordance with the theory presented. In samples cut in the form of parallelepipeds the behaviour is explained by a n⁺⁺-n^-n⁺ structure of the Sb doped Au contacts alloyed to Si, leading to a zone with high field strength always near the cathode if both contacts are equal. If there is an inhomogeneity near one side of the dumb-bell or parallelepiped shaped samples the domain is created always at that end. In each case the region of the static high field domain increases with growing voltage applied until it occupies the whole sample. The mean field strength within the domain amounts to 140 to 200 V/cm varying for different samples and temperatures, but the field strength Outside the domain remains at 30 to 45 V/cm.