Characterization of aluminum-alloyed contacts by diode recovery measurements

On silicon diodes possessing a base width to minority carrier diffusion length ratio around one and aluminum-alloyed contacts, a dependence of storage times from absolute values of forward and reverse currents is observed which can be described by a constant leakage current. To explain this phenomena it is not possible to characterize this type of contact with a single recombination velocity. A formal proof is given by a modification of the Kuno treatment of this problem and the diode behavior is represented by an equivalent circuit consisting of a long-base diode and a resistor in parallel. In addition the lifetimes after Kuno and Kingston are compared.