In-situ flying height testing technology

As the technology goes to sub-10 nm flying height, there exists the high likelihood of slider disk interaction, and it becomes even more important to characterize the dynamic slider-lube-disk interaction. Due to the use of special glass disk, it is difficult for the commercial optical FH tester to test this interaction. The proper way to study this kind of interaction issue is the in-situ flying height testing technology. In this work, the triple harmonic method is selected to test FH in-situ, and the testing hardware had been setup. The accuracy of the developed in-situ FH test setup is within 2% of magnetic spacing between head and medium. The experimental results indicate that the nonlinearity of R/W process does not influence the FH testing much, and the testing setup also has good off-track capability of FH testing.