Method of making a thin film merged MR head with aligned pole tips

A method of making a merged MR head which includes an MR read head and a write head, the MR read head including first and second shield layers S1 and S2, first and second gap layers G1 and G2 sandwiched between the first and second shield layers S1 and S2 and an MR element sandwiched between the first and second gap layers G1 and G2, and the write head including bottom and top pole pieces P1 and P2 which extend from an air bearing surface (ABS) to and including a back gap, the bottom pole piece P1 comprising the second shield layer S2, the bottom pole piece P1 having pole tip elements PT1a and PT1b which extend between the ABS and a zero throat level and the top pole piece P2 having a pole tip element PT2 which extends between the ABS and the zero throat level, the pole tip element PT1b being a pedestal with respect to the second shield layer S2, the bottom pole P1 and the pole tip element PT1a, the second shield layer S2 comprising the pole tip elements PT1a and PT1b, a gap layer G sandwiched between the pole tip elements PT1b and PT2, and each of the pole tip element PT2, the gap layer G and the pole tip element PT1b having first and second vertical sidewalls, the first vertical sidewalls of the pole tip element PT2, the gap layer G and the pole tip element PT1b lying contiguously in a first vertical plane and the second vertical sidewalls of the pole tip element PT2, the gap layer G and the pole tip element PT1b lying contiguously in a second vertical plane, the first and second vertical planes being perpendicular to the ABS and spaced from one another at the ABS by a distance w to define the track width of the merged MR head, the method of making comprising:

• depositing a first magnetic layer from the ABS to and including the back gap to form:
• (1) the second shield layer S2 of the MR read head and
• (2) the bottom pole P1 with an undefined pole tip portion between the ABS and the zero throat level and a back portion between the zero throat level and the back gap;
• depositing the gap layer G on top of the first magnetic layer from the ABS to the zero throat level;
• depositing a second magnetic layer on top of the gap layer G and above the first magnetic layer to form the top pole piece P2 with a defined pole tip element PT2 which has first and second vertical sidewalls;
• and
• directing at least one ion beam at the first magnetic layer in an area of the undefined pole tip portion of the bottom pole P1 in a direction which is substantially parallel to the ABS and at an angle .theta. to the first and second vertical sidewalls of the pole tip element PT2 using the pole tip element PT2 as a mask to notch the first magnetic layer on each side of the pole tip element PT2, the notches leaving the first magnetic layer with a vertical pedestal, the vertical pedestal being the pole tip element PT1b and providing the pole tip element PT1b with first and second vertical sidewalls, and the magnetic layer, less the pedestal, between the ABS and the zero throat level comprising the pole tip element PT1a, the first vertical sidewalls of the pole tip elements PT1b and PT2 being aligned in a first vertical plane and the second sidewalls of the pole tips PT1b and PT2 being aligned in a second vertical plane, the first and second vertical planes being perpendicular to the ABS and spaced from one another at the ABS to define the track width w of the merged MR head.