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

We review our recent studies on the reactions of hydrogen with transition-m etals (Pd, Pt, Ag, and Au) in crystalline Si. Hydrogen was incorporated int o the samples by wet-chemical etching. Deep-level transient spectroscopy (D LTS) 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, complexes. AU complexes with i = i , 2 are electrically active. Striking similarities are found for isoelectro nic complexes, e.g. Pt-H, and Au-H,. Transition metal complexes with more t han three hydrogen atoms are likely to be electrically passive. All hydroge n related complexes disappear after heat treatments above 600 K for several hours. (C) 1999 Elsevier Science S.A. All rights reserved.