CMOS compatible W/CoFeB/MgO spin Hall nano-oscillators with wide frequency tunability

Abstract

We demonstrate low-operational-current W/Co20Fe60B20/MgO spin Hall nano-oscillators (SHNOs) on highly resistive silicon (HiR-Si) substrates. Thanks to a record high spin Hall angle of the β-phase W (θSH = −0.53), a very low threshold current density of 3.3 × 107 A/cm2 can be achieved. Together with their very wide frequency tunability (7–28 GHz), promoted by a moderate perpendicular magnetic anisotropy, HiR-Si/W/CoFeB based SHNOs are potential candidates for wide-band microwave signal generation. Their CMOS compatibility offers a promising route towards the integration of spintronic microwave devices with other on-chip semiconductor microwave components.