In order to achieve polariton lasing at room temperature, a new fabrication methodology for planar microcavities is proposed: a ZnO-based microcavity in which the active region is epitaxially grown on an AlGaN/AlN/Si substrate and in which two dielectric mirrors are used. This approach allows us to simultaneously obtain a high-quality active layer together with a high photonic confinement as demonstrated through macro-, micro-photoluminescence (µ-PL) and reflectivity experiments. A quality factor of 675 and a maximum PL emission at k ~ 0 are evidenced thanks to µ-PL, revealing an efficient polaritonic relaxation even at low excitation power.