Microelectronic Engineering 55 (2001) 93–99 www.elsevier.nl / locate / mee AFM measurement of the grain size in polycrystalline titanium silicides a, a a b a * F. Cazzaniga , G. Pavia , A. Sabbadini , S. Spiga , G. Queirolo a STMicroelectronics, 20041 Agrate Brianza ( MI ), Italy b Laboratorio MDM-INFM, 20041 Agrate Brianza ( MI ), Italy Abstract In titanium silicide, the transition from the high (C49) to the low resistivity phase (C54) is difficult in small areas. This has been attributed in the literature to the lack of the nucleation sites for phase transition in small areas [1]. The mean grain size is directly related to the nucleation point density and its evaluation is important in obtaining data on nucleation mechanism of a new crystalline phase. TEM and SEM cross sections show that a silicon ridge is formed on the silicon substrate at the silicide grain boundaries, due to the equilibrium between the forces related to the grain–grain and to the grain–silicon interface energies [2,3]. AFM measurements have been performed on the interface between silicon and silicide after the removal of the silicide film. The grain boundaries of the silicide were imaged using the silicon ridges, allowing us to obtain unambiguous and statistically relevant data on the grain size.  2001 Elsevier Science B.V. All rights reserved. Keywords: Titanium silicide; AFM; Grain size 1. Introduction The measurement of the mean grain size in a polycrystalline film is of high interest because this parameter can give useful information about deposition, crystallisation of amorphous layer, and phase transition phenomena. TEM observations, both in cross-sections and in plan, are usually employed to image the titanium silicide grains and measure their size. These measurements present some problems particularly on cross sections, which give information on a quite limited number of grains, and tend to underestimate their size. Plan view TEM observations are very useful for flat polycrystalline films, and are able to put in high contrast a number of grains. However, titanium silicide films grown on real silicon surfaces are not flat, and this decreases the number of visible grains. AFM measurements are commonly performed to characterise the grain size of different polycrystalline materials used in microelectronics like aluminium, polysilicon and titanium. Measurements are usually performed on *Corresponding author. E-mail address: francesco.cazzaniga@st.com (F. Cazzaniga). 0167-9317 / 01 / $ – see front matter  2001 Elsevier Science B.V. All rights reserved. PII: S0167-9317(00)00433-0