High‐Rate Deposition and Characterization Study of CoZrO Films for On‐Chip Power Applications

On‐chip integration of inductors and transformers can enable power converters with high frequency, high control bandwidth, and low interconnect loss for high‐current computing applications. Nevertheless, depositing high‐quality magnetic materials that are back end of line compatible with complementary metal‐oxide‐semiconductor (CMOS) technology, affordable (fast deposition), but optimized for these applications is challenging. Nanogranular materials, such as CoZrO, are promising candidates as core materials for on‐chip magnetic components due to their low coercivity and high saturation flux density. However, the deposition rates of these materials remain limited, which limits their cost effectiveness. Herein, the high‐rate reactive magnetron sputtering process for homogeneous CoZrO coatings with soft magnetic properties at deposition rates 5 times higher compared to literature is presented. An extensive study is presented on the properties of CoZrO including vibration sample magnetometry, transmission electron microscopy, scanning electron microscopy, and X‐ray diffraction characterization results. The findings underscore the importance of maintaining elevated Co:O (at%) ratios up to 75:15 and ensuring uniform microstructure to achieve optimal magnetic properties, which are enabled by the closed‐loop O 2 controller in our sputtering process.