Automated active feedback slice and view milling of magnetic head cross-sections

摘要

A dual/beam FIB/SEM system and method for operating such a system are provided. A micrograph of a throat height view of a magnetic writer is obtained through iterative milling and repeated evaluation of the leading bevel angle or pole length. In some cases, the milling depth for a next iteration may be modified based on evaluation of the leading bevel angles of the current iteration.

主权项

1. A method, comprising:
obtaining a first micrograph of an air bearing surface of a magnetic head pole; using the first micrograph, measuring the width of the pole at the air bearing surface and measuring the length of the pole at the air bearing surface; if the width of the pole at the air bearing surface is greater than a lower width threshold and less than an upper width threshold, then performing the steps of:
determining an initial milling region proximal to an outer edge of the pole;milling the pole within the initial milling region to form a milled surface; andperforming at least one iteration, each iteration comprising:
obtaining an iterative micrograph of the pole at the milled surface;using the iterative micrograph, measuring a leading bevel angle and a trailing bevel angle of the pole or measuring the length of the pole at the milled surface; andif the difference between the leading bevel angle and the trailing bevel angle is greater than a bevel angle threshold or if the difference between the length of the pole at the milled surface and the length of the pole at the air bearing surface is greater than a pole length threshold, then milling the pole by a milling amount and performing a next iteration, or else providing the iterative micrograph for metrology.