In this work we mainly report on the analysis of polycrystalline 3C-SiC films grown by electron cyclotron resonance-chemical vapor deposition (ECR-CVD) on 4 in. (1 0 0) and (1 1 1) c-Si wafers, using a H-2 + SiH4 + CH4 gas mixture at substrate temperatures in the range 930-1050 degreesC. Structural properties of the films were analyzed by X-ray diffractometry, micro-Raman spectroscopy and transmission electron microscopy, while the elemental composition was determined by Rutherford backscattering (RBS) technique. Micro-Raman measurements performed on the SiC layers show a peak around 796 cm(-1) due to transversal optical phonons of the crystalline SiC matrix, while neither carbon clusterization in graphitic phase nor Si clusterization in amorphous phase was observed. TEM analyses show a polycrystalline columnar structure with lateral crystal dimensions ranging from 300 up to 1400 Angstrom. The crystals orientation is very close to that of (1 0 0) and (1 1 1) Si substrates, as revealed by X-ray and electron diffraction.