Nanoscale Thermal Mapping of HAMR Heads Using Polymer Imprint Thermal Mapping

A number of systems require high-resolution, non-perturbative thermal mapping. This need is especially apparent for heat-assisted magnetic recording (HAMR), a technology developed to increase the areal density of magnetic storage. In HAMR, plasmonic antennas are used to heat magnetic media by hundreds of degrees in a nanoscale region. Understanding the antenna's temperature is critical, but the available methods for high-resolution thermal mapping are dominated by experimental artifacts. In order to measure the temperature distributions of a plasmonic antenna without a major perturbation, a new technique, polymer imprint thermal mapping (PITM), was developed, which relies on the thermal response of a thin polymer film to report temperature. The polymer permanently cross-links upon heating, so the thermally induced height change of the polymer film is directly correlated with the sample temperature. It is experimentally shown that PITM creates thermal maps that are far superior to conventional scanning thermal microscopy. In addition, the modeled thermal distributions show remarkable agreement with the measured PITM thermal maps.