Characteristics of aluminum-titanium electrical contacts on silicon

Abstract

An aluminum-titanium metallization scheme for use in silicon integrated circuits is described. This metallization can produce high-conductance electrical contacts with negligible dissolutions of silicon. The desirable contact is lost, however, if a TiAl3 reaction product is allowed to consume the entire Ti layer. The TiAl3 forms during the postmetallization heat treatment used to stabilize the electrical characteristics of the contact. The Ti layer is found to be consumed in this reaction at a rate proportional to t1/2, where the rate constant is determined to be d=d0 exp(−Ea/kT), where d0 ≈ 0.15 cm2/sec and Ea ≈ 1.85 eV. This rate constant can be used to determine the thickness of titanium layer necessary to produce the desirable electrical contact.

Depth profile analysis of minor elements by GD-OES: Applications to diffusion phenomena

“…3. According to [8,9] the intermetallic phase -Al Ti grows at the interface, with the diffusion coefficient following the Arrhenius equation with a frequency factor of D "0.15 cms\ and an activation energy of Q"1.85 eV. This interface layer can be clearly seen in the profile of Fig.…”

Aluminum-Based Rear-Side PVD Metallization for nPERT Silicon Solar Cells

“…It is reported that the compound TiAl 3 is formed at these temperatures [28], [30]. The reaction kinetic of TiAl 3 formation is empirically determined by Bower [30]. The amount of Ti consumed in the reaction with Al to form TiAl 3 increases proportionally to the square of heating time.…”

“…Since a contact formation annealing at 400 • C is used, we only consider Ti aluminides in this study. It is reported that the compound TiAl 3 is formed at these temperatures [28], [30]. The reaction kinetic of TiAl 3 formation is empirically determined by Bower [30].…”

The kinetics of two-stage formation of TiAl3 in multilayered Ti/Al foils prepared by accumulative roll bonding

“…The early stages of phase reaction between Ti and Al were characterised by the initial formation of TiAl 3 in both bulk and thin film samples for any composition and for temperature up to the melting point of Al [9][10][11][12][13][14]. The intermetallic phases, i.e., g-TiAl, a 2 -Ti 3 Al and TiAl 2 , were not observed in the early stages of the reaction.…”