NdF3 layers were grown on Si (I 1 1) substrates at 400degreesC, 550degreesC and 700degreesC by molecular beam epitaxy. Their images scanned by atomic force microscope showed that the NdF3 layers on Si (I 1 1) substrates grew as islands with spiral step patterns. As function of growth temperature, their interfacial characteristics such as orientational alignment, defects, and crystallinity were investigated by transmission electron microscope (TEM) combined with selected area electron diffractorneter. In particular, the relationship between interfacial microstructure and crystalline quality of overall NdF3 layers were explained by comparing the result of TEM observation with full-width at half-maximum values for X-ray rocking curves of both (1 1 (2) over bar 0) in-plane and (0 0 0 2) out-of-plane diffractions of NdF3 layers. (C) 2002 Elsevier Science B.V. All rights reserved.