A structural study of the initial interface region formed by titanium on silicon (111) was undertaken. Thin films (100 A˚) of titanium were deposited in ultrahigh vacuum (UHV) conditions onto atomically clean silicon(111) wafers and annealedinsituat 25 °C intervals between 300 and 475 °C. Structural characterization of the evolving interface was performed primarily via extended x‐ray absorption fine structure (EXAFS) measurements. Results indicate that a major structural rearrangement takes place between 400 and 425 °C. EXAFS fitting analysis reveals this transition to be from a disordered TiSi‐like phase to a more ordered C49‐like disilicide state. The results are compared with those previously reported for the zirconium:silicon system. ©1996 American Institute of Physics.