Improvement of Inductor Performance Parameters With Thin 20 nm Permalloy Patterns

Abstract

In earlier works, it was shown that the controlled formation of magnetic domains by tailoring shape, size and thickness of Permalloy patterns improves the performance of the inductor compared to bulk thin films. Also, it was shown that 60 nm thick micromagnetic patterns with cross tie walls give better performance compared to 92 nm thick patterns which have asymmetric Bloch walls, owing to larger stray fields. In this work, we compare 20 nm thin film patterns with 60 nm and 92 nm micromagnetic patterns. Experimental results show that inductor embedded with the thinner film i.e. 20 nm permalloy patterns having Neel domain wall provide more improvement in inductance density and quality factor as compared to thicker 60nm having cross-tie domain wall and 92 nm with asymmetric Bloch wall over a broad range of frequencies encompassing the 5G spectrum. There is a 118% peak increment in inductance density and a 204% peak improvement in quality factor in the inductor incorporated with 20 nm thin permalloy patterns.