PROPERTIES OF TANX FILMS AS DIFFUSION-BARRIERS IN THE THERMALLY STABLE CU SI CONTACT SYSTEMS/

The properties of Ta2N and TaN compound films as a diffusion barrier b etween Cu and Si have been investigated by examining compositional dep th profiles obtained by Auger electron spectroscopy. The use of a Ta2N barrier is effective for improving the thermal stability of the conta ct system by raising the silicide formation temperature as compared wi th the use of a Ta barrier. The contact system of Cu/TaN/Si is fairly stable due to annealing for 1 h even at 750 degrees C. This is interpr eted by the stability of the TaN compound, which is chemically inert t o Si as well as Cu at this temperature. Eliminating the grain growth o f TaN due to annealing is also effective for suppressing the: physical diffusion through the barrier. (C) 1996 American Vacuum Society.