講演情報
[15p-P07-6]Temperature Dependence of Magnetic Switching and Spin Valve Behaviors in MnAs/InAs/MnAs Double Heterostructure on GaAs (111) B
〇(D)Tauhidul Islam1, Van Thuan Pham1, Soh Komatsu1, Masashi Akabori1 (1.JAIST)
キーワード：
Vertical spin valve、Double heterostructure、MBE
Ferromagnetic (FM)/semiconductor (SC) hybrid structures have garnered interest in spintronics due to their potential in spin field-effect transistors (spin-FETs). We developed MnAs/InAs hybrid systems with promising lateral device performance but limited by lithographic constraints on channel length. To overcome this, we fabricated vertical MnAs/InAs/MnAs double heterostructures (DH) on GaAs 111 B using molecular beam epitaxy (MBE). The InAs channel thickness, adjustable during growth, allows precise control of channel length. To ensure compatibility with MnAs growth, the entire process was performed at about 250 °C below the standard InAs growth temperature about 480 °C. The MBE-grown DH comprised about 400 nm InAs channel between 75 nm top and 150 nm bottom MnAs layers. Magnetization measurements confirmed distinct switching behaviors of the MnAs layers essential for vertical spin valve (VSV) operation. The double steps in the hysteresis curves indicated separate magnetization switching with easier switching at higher temperatures. We fabricated VSV devices from the DH using electron beam lithography and Ar ion dry etching and measured them using an AC lock-in technique across various currents and temperatures. The spin valve signal showed strong temperature dependence with lower magnetization switching fields and increasing signal amplitude at higher temperatures reflecting the impedance mismatch effect between FM and SC. The consistency between DH and VSV behaviors highlighted the robustness of both fabrication and measurement processes. A promising spin injection efficiency was achieved, demonstrating the potential of this structure for vertical spinFET applications.