HYDROGEN PASSIVATION OF GOLD IN P-TYPE SILICON INVOLVING HYDROGEN-GOLD-RELATED DEEP LEVELS

We report on two hydrogen-gold-related deep levels (G2 and G3) in gold-doped p-type silicon. The levels are formed after hydrogenation by wet chemical etching. Using deep-level-transient-spectroscopy depth profiling and capacitance-voltage analysis we demonstrate that the levels are caused by injection of hydrogen into gold-doped silicon. The etching treatment results in a decrease of the gold-donor concentration, which can be fully explained by a corresponding increase of the G2 trap concentration. The results indicate that the G2 level belongs to an electrically active gold-hydrogen (Au-H) complex that changes into an electrically inactive Au-H complex upon heat treatment between 150 and 200-degrees-C. Prolonged heat treatments within this temperature range result in dissociation of these electrically inactive Au-H complexes and the gold-donor concentration approaches its initial value.