Electrical and crystalline properties of seeded-lateral epitaxial Si layers on SiO2 obtained by cw scanning Ar laser irradiation are evaluated as a function of distance from the seeding area. Field effect electron mobility of 600 cm2/V·s, comparable to that of bulk Si, is obtained for almost all grown layers. However, electrical properties near SiO2 edge are found to be somewhat poor. This is related to the existence of dislocations and residual stress discontinuities at the SiO2 edge. Useful application of the multi-region in epitaxial layer for 3-dimensional device structures is also proposed.