Phase equilibria in thin-film metallizations

Abstract

Nature of an intergranular thin−film phase in a highly non−Ohmic metal oxide varistorThe determination of stable tie lines in a ternary phase diagram through a limited number of thinfilm reactions is demonstrated. Ternary phase diagrams are then used to explain the stability of refractory metals, silicides, and nitrides during various integrated circuit processing steps. The W-Si-O, Ti-Si-O, Ti-Si-N, and Ti-AI-N systems serve as examples.

The thermodynamic assessment of the Ti–Si–N system and the interfacial reaction analysis

“…On the basis of the work of Beyers and Sinclair [21] and Wakelkamp [22], Sambasivan and Petuskey [23] again …”

“…The phase diagrams provided by Refs. [21][22][23] show the equilibrium between TiN and Si but not between TiSi 2 and Si 3 N 4 . But Paulasto et al [7] pointed out that TiN and Si could react with each other and form Si 3 N 4 and/or TiSi 2 depending on the activity of nitrogen (see Fig.…”

“…Wakelkamp [22] revised the ternary phase diagram of Beyers and Sinclair [21] at 1300 K, extending the compositional ranges of TiN and Ti 5 Si 3 N x , adding the compounds Ti 3 Si, Ti 5 Si 4 and the terminal solution phase (␣Ti), and pointing out the existence of TiN-TiSi 2 tie line (see Fig. 5).…”

“…Desu and Taylor [19] detected three tie lines: TiN-TiSi 2 , TiN-Ti 5 Si 3 N x and TiN-Si 3 N 4 . Based on the experimental data and the Gibbs free energy data from Barin and Knacke [20], Beyers and Sinclair [21] drew the isothermal section of Ti-Si-N ternary system in the temperature range 973-1273 K (see Fig. 4).…”

Novel multilayered Ti/TiN diffusion barrier for Al metallization

“…It is important to note that the formation of TiAl 3 is more likely to occur in the Al-Ti system than in the Al-TiN system after thermal processing, since thermal stability between Al and Ti layers is lower than that between Al and TiN layers. [22][23][24] Increased thickness of the inserting Ti interlayer will enhance the formation of TiAl 3 compounds, resulting in increased contact resistance. Table I, to explore effects of distribution of inserting Ti interlayer on barrier properties of multilayered Ti/TiN barriers.…”