Chemical vapor deposition of titanium–silicon–nitride films

Abstract

Titanium–silicon–nitride films were grown by metal-organic chemical vapor deposition. At temperatures between 300 and 450 °C, tetrakis(diethylamido)titanium, ammonia, and silane react to form films with average compositions near the TiN–Si3N4 tie line and low impurity contents (C<1.5 at. %, H between 5 and 15 at. %, with no other impurities present). The film resistivity is a strong function of Si content in the films, ranging continuously from 400 μΩ cm for pure TiN up to 1 Ω cm for films with 25 at. % Si. Step coverages of approximately 75% on 0.35 μm, 3:1 aspect ratio trenches, and 35%–40% on 0.1 μm/10:1 trenches are found for films with resistivities below 1000 μΩ cm. These films are promising candidates for diffusion barriers in microelectronic applications.