January 2010 Americas Cover Picture and Story

January 2010 Americas Cover Picture and Story

COVER STORY

The cover is a 3D image of an overhang structure that will become the write pole of a disk drive magnetic recording head.　 The sidewall of the overhang shows surprisingly high-resolution details of regular ripples, the result of standing wave interference during a lithographic process. In its current form the structure is at wafer level.　The structure is made of magnetic metal that will localize the magnetic field to write the bits on a magnetically coated disk.　 To become a head, the structure will be coated with alumina and then the wafer will be sliced and diced such that the narrowest portion of the structure in cross-section　will become the write pole.　By knowing at wafer-level processing the dimension of the write pole successful manufacturing is guaranteeed.

This sample was imaged with Park Systems’ new 3D atomic force microscope. The new XE-3DM, a fully automated AFM system, is designed for overhang and trench profiles, sidewall roughness and imaging, and critical angle measurements. The unique design of the XE-3DM is made possible by deliberately and independently tilting the Z scanner in its patented Crosstalk Eliminated (XE) AFM platform where X, Y and Z scanners are completely and independently decoupled. Unlike flared tips, the probes maintain their high aspect ratio and sharp tip radius, typically less than 10 nm, providing accurate metrology of critical dimensions along with sidewall roughness. The XE-3DM can measure critical dimensions efficiently and image the vertical sidewalls as well as undercut structures at deeper angles. The unprecedented high resolution of sidewall imaging opens the door to new characterization possibilities in measuring the sidewall roughness of nanoscale features, making it possible to enhance semiconductor and photonic device manufacturing.