Drake R. Austin, AV Incorporated/Air Force Research Laboratory, Wright-Patterson AFB, OH
Laser spike annealing (LSA) is a promising technique for rapidly investigating the modification of thin film materials due to thermal annealing. By scanning a focused continuous-wave laser across the thin film surface, localized heating can be achieved with heating/quenching times as short as microseconds and temperatures exceeding 1000 °C. The laser intensity and scan rate can be varied, allowing thousands of distinct annealing conditions to be studied on a single sample, including dwell times several orders of magnitude shorter than what can be achieved with rapid thermal annealing. In this work, LSA is applied to the oxidation of hafnium and MoS₂ thin films, two materials whose oxides have shown promise in neuromorphic device applications. Tunable oxidation is achieved by varying the laser conditions in a controlled oxygen environment, enabling access to a wide range of effective temperatures and heating times. The resulting structural and compositional modifications are characterized using X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy. Simple memristor devices are fabricated using the laser-oxidized materials within a device stack, allowing structure-property-performance relationships to be established by coupling characterization results with device performance metrics.