A perpendicular magnetic recording (PMR) head is fabricated with a pole tip shielded laterally by a separated pair of side shields and shielded from above by an upper shield. The side shields are formed by a RIE process using specific gases applied to a shield layer through a masking layer formed of material that has a slower etch rate than the shield material. A masking layer of Ta, Ru/Ta, TaN or Ti, formed on a shield layer of NiFe and using RIE gases of CH3OH, CO or NH3 or their combinations, produces the desired result. The differential in etch rates maintains the opening dimension within the mask and allows the formation of a wedge-shaped trench within the shield layer that separates the layer into two shields. The pole tip is then plated within the trench and, being aligned by the trench, acquires the wedge-shaped cross-section of the trench. An upper shield is then formed above the side shields and pole.