Test structures for measuring near field transducer disc length

摘要

Systems and methods for using NFT disc test structures for controlling NFT disc length during manufacture of an HAMR writer are disclosed. An NFT is manufactured concurrently with one or more pairs of pin-disc and disc-less test structures. The NFT disc and pin dimensions may be substantially similar to the pin and disc dimensions of the pin-disc test structure. The disc length of the pin-disc test structure is measured as a function of the difference in resistance between the two test structures and other parameters. Capturing the disc length variation subsequently enables adjustment of the NFT electronic lapping guide stripe height to reduce length variation in the NFT pin.

主权项

1. A system for controlling the disc length of a Near Field Transducer (NFT), comprising:
a first test structure comprising a disc and a pin; and a second test structure comprising a pin; wherein the first test structure disc length is determined based on a measured resistance of the first test structure and a measured resistance of the second test structure; and wherein the first test structure disc length is approximately the same as the NFT disc length.