Large current modulation in a GaMnAs-based vertical spin metal-oxide-semiconductor field-effect transistor*

A spin MOSFET is one of the most promising devices for the post-scaling era [1]. Recently, we reported large MR ratios (60%[2] and 5%[3]) in GaMnAs-based vertical spin FETs, which are much larger than those reported in planar spin MOSFETs (~0.1%) [4–6]. However, the present most important challenge for the practical application of the vertical spin FETs is to improve the small current modulation ratios, which are ~20% at most [3]. Here, we present a vertical spin MOSFET exhibiting a large current modulation ratio up to 130%, which is the largest value in vertical spin FETs reported thus far. Comparing the experimental data with calculated results, the electric-field effect on the indirect tunneling current via defect states in the GaAs channel layer is the most probable origin for the large modulation ratio.
[1] S. Sugahara and M. Tanaka, Appl. Phys. Lett. (2004). [2] T. Kanaki et al., Appl. Phys. Lett. (2015). [3] H. Terada et al., Sci. Rep. (2017). [4] R. Nakane et al., Jpn. J. Appl. Phys. (2010). [5] T. Sasaki et al., Phys. Rev. Appl. (2014). [6] T. Tahara et al., Appl. Phys. Express (2015).