Investigation on PECVD-deposited SiO2 underlayer in permalloy-based magnetoelectronic devices

Abstract

This study presents a comprehensive investigation into the dependence among processing conditions, surface properties of the PECVD-deposited SiO2 underlayer, and their consequential impact on the magnetic and film properties of permalloy. The key exploration parameters involve variations in deposition temperature and annealing temperature. By varying the parameters, microstructure changes within SiO2 were firstly analyzed. A thorough characterization of in-plane magnetic features of the Ni81Fe19/SiO2 multilayer film was then undertaken. The results reveal a significant reliance of magnetic anisotropy and coercivity on PECVD SiO2 deposition temperatures, particularly evident for deposition temperatures below 350°C. This effect is attributed to the formation of a suboxide SiOx film at a lower deposition temperature, which typically possesses more dangling bond and lattice defects, resulting in the formation of surface granular structures after annealing. These characterizations may lead to the identification of optimized processing conditions, which may be used for enhancing the performance of anisotropic magnetoresistance devices with SiO2 as an underlayer. Furthermore, the research findings extend beyond anisotropic magnetoresistance systems, with implications for a broad utilization of magnetoelectronic devices. Overall, the study provides a foundation for informed decision-making in the design and optimization of magnetoelectronic devices, in particular for integrated circuit incorporated devices, highlighting the potential for enhanced functionality through manipulation of processing conditions.