Crystallisation mechanism of amorphous silicon carbide L. Calcagno a , P. Musumeci a,* , F. Roccaforte a , C. Bongiorno b , G. Foti a a Dipartimento di Fisica, Istituto Nazionale di Fisica per la Materia, Unita di Ricerca di Catania, Corso Italia 57, 95129 Catania, Italy b CNR-IMETEM, Stradale Primosole, 50 Catania, Italy Abstract The transition from amorphous to crystalline phase in silicon carbide was investigated by infrared spectroscopy and transmission electron microscopy (TEM). Amorphous silicon carbide films on silicon substrate were deposited by plasma enhanced chemical vapour deposition. Quantitative analysis of the crystalline fraction has been performed by IR measurements. The crystallisation kinetic was monitored by following the evolution of the silicon–carbon bond absorption band in the infrared spectra as a function of the annealing temperature (800–1000 8C) and time. The results indicate that crystallisation occurs through the nucleation and growth of crystalline grains and an activation energy of 5.1 eV for the process has been determined. TEM analysis showed a polycrystalline b-SiC microstructure for the fully crystallised films. # 2001 Published by Elsevier Science B.V. Keywords: Annealing; Grains; Polycrystalline; Bonds 1. Introduction Silicon carbide (SiC) has been receiving an increas- ing interest in the last decade due to its potential applications for electronics and optoelectronics devices. The high bandgap (3.0 eV for 6H–SiC and 3.2 eV for 4H–SiC) together with the thermal stability of the material, is well indicated for high temperature, high power and harsh environment devices applica- tions. Moreover, the high value of thermal conduc- tivity (4.9 W/cm K) and saturation electron velocity ð2  10 7 cm=sÞ are fundamental in terms of power dissipation and high frequency operation of the device, respectively [1–3]. Among the different SiC polytypes, the cubic sili- con carbide (3C–SiC), beyond having high values of electron mobility, critical electric field and thermal conductivity, is the only one that can be epitaxially grown on silicon substrates [4]. In fact, the use of thin crystalline SiC films on silicon substrate, can be very interesting as it combines the excellent proprieties of SiC with the well-known silicon technology and the low substrate cost. However, the production of these SiC films requires the solution of various technologi- cal problems, like a lattice mismatch of about 20% (being the lattice constant 4.36 A ˚ in cubic silicon carbide and 5.43 A ˚ in silicon). In spite of this large mismatch, it is still possible to grow SiC epitaxially on silicon, but at deposition temperature higher than 1200 8C [5,6]. The high temperatures (1300 8C) needed in the chemical vapour deposition technique for the growth of 3C–SiC on silicon substrate leads to an unintentional Applied Surface Science 184 (2001) 123–127 * Corresponding author. Tel.: þ39-095-7195420; fax: þ39-095-383023. E-mail address: musumeci@ct.infn.it (P. Musumeci). 0169-4332/01/$ – see front matter # 2001 Published by Elsevier Science B.V. PII:S0169-4332(01)00487-1