Similarities in the electrical properties of transition metal–hydrogen complexes in silicon

Abstract

We review our recent studies on the reactions of hydrogen with transition-metals (Pd, Pt, Ag, and Au) in crystalline Si. Hydrogen was incorporated into the samples by wet-chemical etching. Deep-level transient spectroscopy (DLTS) on Schottky diodes reveals several transition metal–hydrogen complexes in n- and p-type samples. From DLTS profiling, we are able to estimate the number i of hydrogen atoms in the TM–H i complexes. All complexes with i=1, 2 are electrically active. Striking similarities are found for isoelectronic complexes, e.g. Pt–H 2 and Au–H 1. Transition metal complexes with more than three hydrogen atoms are likely to be electrically passive. All hydrogen related complexes disappear after heat treatments above 600 K for several hours.