Microelectronic Engineering 50 (2000) 153–158 www.elsevier.nl / locate / mee Investigation of C49–C54 TiSi transformation kinetics 2 a, a a b b b * G. Ottaviani , R. Tonini , D. Giubertoni , A. Sabbadini , T. Marangon , G. Queirolo , c F. La Via a Istituto Nazionale di Fisica della Materia e Dipartimento di Fisica, Via Campi 213 / a, 41100 Modena, Italy b ST-Microelectronics, Via Olivetti 2, 20040 Agrate Brianza, Milano, Italy c IMETEM CNR, Stradale Primosole 50, 195121 Catania, Italy Abstract The C49 ⇒ C54 TiSi polymorphic transformation has been investigated trying to elucidate the relative role played by 2 nucleation and growth in silicide formation. Samples having an amorphous layer and C54 seeds have been made by heat treatment of a Ti / Si bi-layer structure and subsequent suitable Ar ion implantation. In situ resistance measurements performed during heat treatments in controlled and purified atmosphere at constant heating rates and ex situ X-ray 4 1 diffraction, MeV He backscattering spectrometry and cross-section transmission electron microscopy have been used to characterize the samples. The results show that in a sample with C49 the C54 nucleation occurs at 8008C; when C54 seeds are present the growth is appreciable already at temperatures as low as 400–5008C. It has also been shown that nucleation and growth of the C49 phase is a process competitive to the growth of the C54 phase.  2000 Elsevier Science B.V. All rights reserved. Keywords: Phase transition; Titanium silicide; Polymorphic transformation 1. Introduction A titanium film deposited on silicon reacts [1–6] after heat treatment and forms TiSi compound; 2 high resistivity C49 grows first followed by the low resistivity thermodynamic stable phase C54. In the case of crystallization of an amorphous layer [7–9] with an average composition of TiSi , the C49 2 phase appears at temperatures around 4008C followed at about 8008C by the C54 phase. Bi-layers and alloys behave, from this point of view, substantially in the same way; in both cases the process is kinetically controlled and the question if nucleation or growth rate is the limiting step in the C49 ⇒ C54 transformation is still an open question. The purpose of the present paper is to try to elucidate the role of the nucleation and of the growth rate by performing a series of experiments where an amorphous TiSi layer with C54 seeds are 2 produced. If after a suitable heat treatment C54 continues to grow the C49 ⇒ C54 transformation is *Corresponding author. E-mail address: ottaviani.giampiero@unimo.it (G. Ottaviani) 0167-9317 / 00 / $ – see front matter  2000 Elsevier Science B.V. All rights reserved. PII: S0167-9317(99)00276-2