[en] A 300-nm-thick PbZr_0.3Ti_0.7O₃ [PZT(30/70)] film was sputtered onto LaNiO₃ (LNO)/Si(100) substrates at a substrate temperature of 200degC and then annealed under an oxygen pressure of 4 MPa at 400degC. The amorphous phase of the as-sputtered PZT(30/70) film was transformed to a highly (h00)-oriented perovskite phase by high-oxygen-pressure-processing (HOPP). The results of electrical measurements such as of polarization (P) as functions of applied electric field (E) (P-E hysteresis loops), the capacitance as functions of the applied dc electric field (C-E loops), and the dielectric constant (ε_r) and dissipation factor (tan δ) suggested that ferroelectric properties of PZT(30/70) films were largely improved by HOPP. We consider that HOPP is compatible with currently existing silicon-based technology, which is characterized by incorporating sputtering and a processing temperature limit of ∼450degC. The P-E hysteresis loops obtained from a prototype of 128x128 uncooled infrared detector arrays prepared by HOPP supported the good ferroelectricity with a high pyroelectric coefficient. (author)