Electrically Tunable Integrated Thin‐Film Magnetoelectric Resonators

Abstract

devices. [1][2][3][4][5][6]9,10] In each of these cases, an electric field applied to the device couples either directly or indirectly to the magnetization and changes its state. This magnetoelectric coupling property can be found in single-phase multiferroic materials (those exhibiting both ferroelectricity and ferromagnetism) or multiphase material systems (combining different types of ferroic materials into composites). In this work, we develop the first thin-film magnetoelectric composite to be completely integrated in a semiconductor device process and demonstrate its performance in the form of a tunable waveguide resonator. These integrated magnetoelectric resonators extend the reach of magnetoelectrics into yet another field-that of radio-frequency (RF) wireless communication-and demonstrate tunability across several wireless channels using as little as ≈6 V µm electric field.To avoid congestion of wireless communication channels, wireless electronics must be able to be tuned broadly across multiple channels, while also maintaining small form factors for portability. Various methods have been proposed for broadband tunability, mostly involving variable capacitors or inductors in resonant circuits. [9,[12][13][14][15] However, resonators can also take other forms, such as waveguides, which can be tuned by changing either their effective capacitance [16] or effective inductance. Common drawbacks of many of these previous methods are their incompatibility with semiconductor circuit integration, bulk size, or limited tunability range. In this work, we explore the design and integration of thin-film magnetoelectrics for tunable coplanar waveguide resonators. These devices aim to satisfy semiconductor integration requirements while simultaneously providing large tunability by means of electrical control of magnetization.We designed the tunable resonator device shown in Figure 1 as an RF quarter-wavelength resonator, whose resonance is based on the effective permeability and permittivity of the material stack. For tunability of the resonance frequency, we utilize a two-phase magnetoelectric composite in which the magnetic permeability can be varied through electric field control of strain. A coplanar waveguide on the surface of the structure carries the wave such that its propagation is influenced by the underlying magnetoelectric stack. The magnetoelectric is composed of a magnetostrictive ferromagnetic layer on top of a piezoelectric/electrodes combined layer, with the silicon Magnetoelectrics have attracted much attention for their ability to control magnetic behavior electrically and electrical behavior magnetically. This feature provides numerous benefits to electronic systems and can potentially serve as the bridge needed to integrate magnetic devices into mainstream electronics. Here, this natural next step is pursued and thin-film integrated magnetoelectric devices are produced for radio-frequency (RF) electronics. The first fully integrated, thin-film magnetoelectric modulators for tunable RF electronics...

Recent Progress in Devices Based on Magnetoelectric Composite Thin Films

“…However, recent developments in thin-film fabrication techniques have provided more alternatives for the fabrication of different ME heterostructures, where ferromagnetic and ferroelectric constituents can be coupled at an atomic level to achieve good interfacial coupling in strain-mediated ME composites [4]. In this context, different types of ME thin films, particulate heterostructures (0-3), vertical heterostructures (1)(2)(3), and laminate (2-2) (Figure 1) have been fabricated using pulsed laser deposition (PLD) [7,8], molecular beam epitaxy (MBE) [9,10], metal-organic chemical vapor deposition (MOCVD) [11], spin coating [12], and sputtering [13,14]. In particular, epitaxial growth techniques (PLD, MBE, and sputtering) are more feasible than the rest for fabricating single crystalline or self-assembled oxide heterostructures with more control over the structures.…”

Vector analysis of electric-field-induced antiparallel magnetic domain evolution in ferromagnetic/ferroelectric heterostructures

“…Therefore, electric field (E-field), rather than electric current, has been proposed as an energy-efficient alternative to manipulate magnetization [7][8][9]. Significant progress has been made in E-field control of macroscopic magnetic properties of multiferroic heterostructures, including the magnetic anisotropy [10,11], the exchange bias [12,13], the magnetoresistance [14,15], the magnetic permeability [16], and the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction [17], etc. In consideration of the potential applications in micro/nano devices, recent attention has been turned toward the E-field manipulation of micromagnetic elements, such as magnetic domains [18][19][20][21].…”

Low-Temperature Growth of AlN Films on Magnetostrictive Foils for High-Magnetoelectric-Response Thin-Film Composites

“…The notation, such as 1–3, 0–3, and 2–2, is used to classify the structure of an ME composite in which the number describes the dimensional geometry of each phase . Various deposition techniques, such as electrochemical coating, , magnetron sputtering, , pulsed laser deposition (PLD), − spark plasma sintering, molecular beam epitaxy (MBE), , and metal–organic chemical vapor deposition (MOCVD), were used to fabricate ME composites.…”