Temperature Dependence of Critical Device Parameters in 1 Gb Perpendicular Magnetic Tunnel Junction Arrays for STT-MRAM

This paper investigates the temperature-dependent behaviors of critical device parameters in 1 Gb perpendicular magnetic tunnel junction (pMTJ) arrays from 25 °C to 125 °C. Despite the fact that pMTJ (45–50 nm in diameter) attributes are generally degraded at elevated temperatures, this paper suggests that an adequate combination of critical device parameters can be obtained through systematic materials and process engineering, including
$H_{c}$
(1760 Oe at 25 °C versus 750 Oe at 125 °C),
$H_{{\mathrm{\scriptscriptstyle OFF}}}$
(<100 Oe), tunneling magnetoresistance ratio (150% versus 115%),
$\Delta $
(71 versus 52),
$I_{c}$
(120 versus
$97~\mu \text{A}$
), and
$V_{{\mathbf {BD}}}$
(1.55 versus 1.43 V). In addition, pMTJs with two different free layers were comparatively assessed to link pMTJ film properties to the temperature sensitivity of device parameters.