Erbium silicide films were grown in high vacuum (10-8 Torr) on (100) silicon substrates by erbium evaporation on a heated substrate and subsequent annealing. The substrate temperature was between 400-450°C and a second annealing step was given at 800-870°C for 30 min. Films with a thickness in the range of 40-50 nm were prepared. X-ray and electron diffraction were used for the characterisation of the grown films. Transmission electron microscopy characterisation revealed the very high crystalline quality of the films. They were almost single crystalline, of very large 'grains', up to a few hundreds of nm, slightly misoriented with respect to each other. The erbium silicide was found to possess a modulated structure, derived from a basic one of the ThSi2 type.