Method for fabricating a pole tip in a magnetic transducer using feed-forward and feedback
AssigneeHitachi Global Storage Technologies Netherlands B.V.
InventorsNegar Karimi, John I. Kim, Andrew Crehan Walker, Yeak-Chong Wong
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Abstract
Methods for fabricating pole piece tips for a magnetic transducer are disclosed. The ion-milling operations for trimming P2 and notching P1 are controlled using feed-forward and feedback. The preferred method of the invention includes steps for setting four time values used in different phases of the ion-milling process based on feed-forward and feedback of measured values including the P2 width measured in the mask, multiple P2B measurements and measurement of the notch depth.
Claims17
A method of fabricating a thin film magnetic head comprising the steps of:
- patterning a photolithographic mask for a P2 pole piece on a wafer;
- measuring a P2 width in the photolithographic mask;
- depositing a thin film for P2 over the wafer;
- setting a new time T1 for a first rough trimming of P2 using positive feed-forward of the P2 width in the photolithographic mask to adjust a previous value of T1;
- and
- milling the wafer for the new time T1.
A method of fabricating a thin film magnetic head comprising the steps of:
- patterning a photolithographic mask for a P2 pole piece on a wafer;
- measuring a P2 width in the photolithographic mask;
- depositing a thin film for P2 over the wafer;
- setting a new time T1 for a first rough trimming of P2 using feed-forward of the P2 width in the photolithographic mask to positively adjust a previous value of T1 and feedback from a first measurement of P2B from a previous wafer to positively adjust a previous value of T1;
- performing the first rough milling the wafer for the new time T1;
- setting a new time T2 for a second rough trimming of P2 using feed-forward of a P2B width measured after the first rough milling the wafer to positively adjust a previous value of T1 and feedback from a second measurement of P2B from a previous wafer to positively adjust a previous value of T2;
- and
- performing the second rough milling the wafer for the new time T2.
A method of fabricating a thin film magnetic head comprising the steps of:
- depositing a thin film for P1 over a wafer;
- depositing a thin film for a gap layer over the wafer;
- patterning a photolithographic mask for a P2 pole piece on a wafer;
- measuring a P2 width in the photolithographic mask;
- depositing a thin film for P2 over the wafer;
- performing at least a first rough milling of P2 for time T1 using the P2 width in the photolithographic mask to positively adjust the time T1;
- performing a milling operation on the wafer for time T3 to notch P1;
- and
- performing a milling operation on the wafer for time T4 to fine trim P2B using the P2 width in the photolithographic mask to negatively adjust the time T4.
Dependencies are inferred from the claim text.