(Pb_1−xCa_x)TiO₃ perovskite thin films with nominal compositions of (Pb_0.76Ca_.24)TiO₃ (ferroelectric) and (Pb_0.50Ca_0.50)TiO₃ (relaxor-ferroelectric) were prepared on silicon substrates at low temperatures compatible with those used in Si-technology. The technique used for the processing of these films was ultraviolet (UV) sol-gel photoannealing, using photo-sensitive precursor solutions and UV-assisted rapid thermal processing. The UV-irradiation and thermal treatment of the solution-derived films (gel films) were carried out in air or in oxygen. In both cases, the formation of the perovskite occurred at the same temperature, and this temperature increased as the Ca²⁺ content increased. Thus, full-perovskite films of (Pb_0.76Ca_.24)TiO₃ were obtained at 723 K whereas those of (Pb_0.50Ca_0.50)TiO₃ were formed at 773 K. Well-defined ferroelectric hysteresis loops were measured in the (Pb_0.76Ca_.24)TiO₃ films, with values of remanent polarization of P_r ∼ 11 μC cm⁻² and coercive fields for the films processed in oxygen lower than those of the films processed in air, E_c ∼ 164 and ∼226 kV.cm⁻¹, respectively. These films showed a ferro-paraelectric transition at close temperatures of T_max ∼ 605 K, although with higher values of the permittivity for the film processed in oxygen, k ∼ 567 at 10 kHz. The (Pb_0.50Ca_.50)TiO₃ films had a diffuse ferro-paraelectric transition with a relaxor-like character, also with higher k values for the films prepared in oxygen, k ∼ 179 at T_max ∼ 20 K. The possible use of these materials in silicon integrated multifunctional devices is discussed in this paper.