Electrical characterization and modelling of high energy pre-amorphized P+N silicon junctions

Shallow P + N junctions were obtained using germanium pre-amorphization step to reduce the high diffusivity of boron implanted in silicon. The germanium implantation step was performed under different conditions of temperature: ambient temperature and nitrogen temperature. P-type doping was obtained by boron implantation at relatively low energy. To characterize and simulate the electrical behaviour of such samples, steady state current–voltage measurements have been performed at different temperatures varying between 172 and 294 K. The results show a close dependence between the current–voltage characteristics of the samples and their technological parameters of manufacturing. The pre-amorphization step at ambient temperature seems to improve the electrical behaviour of the junction. To simulate the electrical characteristics of the studied samples, a reliable model has been developed based on the classical Spice formulas and taking into account additional phenomena. The simulated curves satisfactorily fit the experimental results for all the samples.