A perpendicular magnetic recording write head has a write pole, a trapezoidal-shaped trailing shield notch, and a gap between the write pole and notch, with the gap being formed of a nonmagnetic mask film, such as alumina, a nonmagnetic metal protective film and a nonmagnetic gap layer. The write pole has a trailing edge that has a width substantially defining the track width and that faces the front edge of the notch but is spaced from it by the gap. The write pole has nonmagnetic filler material, such as alumina, surrounding it except at its trailing edge, where it is in contact with the gap. A reactive ion beam etching (RIBE) process removes the filler material at the side edges of the write pole and thus widens the opening at the side edges. The nonmagnetic metal film protects the underlying mask film and write pole during the widening of the opening. The gap layer and trailing shield notch are deposited into a widened opening above the write pole, so the sides of the notch diverge to cause the generally trapezoidal shape.