Improving Gauge Capability for High-Speed Process Control (AN515)

In the data storage industry, hard drives manufacturers maintain high-volume, 24/7 production, while holding nanometer-scale tolerances and meeting ever-decreasing price points. To achieve these goals, the industry works closely with key equipment vendors, plotting road maps for the next generations of hard drives. Veeco recently worked with manufacturers to address the measurement and control of a critical parameter of the read/write head. The collaboration resulted in a series of improvements, designed into the latest Wyko® Optical Profilers, which provide production measurements with 1-sigma repeatability of less than 0.3 angstroms.

As the data density of hard drives continues to increase, the data track widths and bit sizes shrink accordingly. Writing and reading smaller bits demands careful control of the "magnetic spacing," the distance from the disk's magnetic layer to the read/write poles in the head flying over the disk's surface. In the newest hard drive designs, the magnetic spacing is only 20nm, and the value is decreasing.