Preparation of Ta2Al intermetallic compound films and their application as diffusion barriers to Cu penetration

Autor: Ohta, Akira, Noya, Atsushi, Takeyama, Mayumi, Taguchi, Masahiro, Sase, Touko, Sasaki, Katsutaka
Zdroj: Thin Solid Films; May 1996, Vol. 278 Issue: 1-2 p6-11, 6p
Abstrakt: The thermal stability of the CuTa2AlTaSicontact system, in which the intermetallic compound film of Ta2Al is used as a diffusion barrier to copper penetration, has been studied using Auger electron spectroscopy analysis. Although the examined contact system degrades by the interfacial reaction of silicide formation at the TaSiinterface due to annealing, the system tolerates annealing at 650 °C for 1 h if the Ta layer is considered as a consumable barrier. The replacement of Ta with a Ta-W alloy film results in a decrease of the resistivity and an increase of the silicidation temperature due to alloying. By using this alloy film as a layer adjoining to Si, the system of CuTa2AlTa-WSitolerates annealing at 680 °C for 1 h. Even after this annealing, any penetration of Cu is not observed at the CuTa2Alinterface, suggesting that Ta2Al is a promising material as a diffusion barrier to copper overlayer films.
Databáze: Supplemental Index
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