Fast neutron tolerance of the perpendicular-anisotropy CoFeB–MgO magnetic tunnel junctions with junction diameters between 46 and 64 nm. (6th June 2017)

• Record Type: Journal Article
• Authors: Narita, Yuzuru; Takahashi, Yutaka; Harada, Masahide; Oikawa, Kenichi; Kobayashi, Daisuke; Hirose, Kazuyuki; Sato, Hideo; Ikeda, Shoji; Endoh, Tetsuo; Ohno, Hideo
• Is Part Of: Japanese journal of applied physics. Volume 56:Number 8(2017)
• Publication Date: 2017-06-06
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.56.0802B3
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: This work represents the first-ever investigation of the effects of fast neutron exposure on the perpendicular-anisotropy CoFeB–MgO magnetic tunnel junctions (p-MTJs) with practical junction diameters ( D ) between 46 and 64 nm. In this study, 461 p-MTJs, each with a tunnel magnetoresistance (TMR) ratio above 90%, were irradiated with fast neutrons at a total 1 MeV equivalent fluence of 3.79 × 10 12 cm −2, corresponding to 1.90 × 10 11 h irradiation with fast atmospheric neutrons (20 cm −2 h −1 ), without applying a bias voltage. Following irradiation, there were no changes in the properties of these devices, such as their resistance versus magnetic field curves, resistance values in the parallel and anti-parallel states, or TMR ratios, regardless of the neutron fluence. On the basis of these data, the nuclear reactions that occur under the specific experimental neutron irradiation conditions employed in this work are discussed.