Development of wafer level laminated magnetic thin film for integrated voltage regulator application

In this paper we have demonstrated the 12 inch (300 mm) wafer level fabrication and characterization of a laminated CoZrTa-based magnetic thin film stack with excellent magnetic and electrical properties. Clear magnetic anisotropy with low coercivity (∼0.3 Oe) and high permeability (∼500) were achieved. High resistivity (∼92.8 μΩ·cm) was also obtained for a four-fold lamination stack. Adhesive properties of the CoZrTa film were improved by inserting a proper adhesion layer. The film properties fully satisfy the requirements of a magnetic core for the embedded inductor integration. The superior wafer level uniformity of the film indicates it is ready for manufacturing the Integrated Voltage Regulator system.