Open AccessFabrication of pinned magnetic tunnel junctions using a contact shadow mask method
Author(s) -
You Chen,
Yanping Zhao,
Jin En-Ji,
Feifei Li,
Tianxing Wang,
Zeng Zhong-Ming,
Zilong Peng
Publication year - 2004
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.53.2741
Subject(s) - materials science , magnetoresistance , quantum tunnelling , permalloy , shadow mask , condensed matter physics , tunnel magnetoresistance , fabrication , magnetic field , layer (electronics) , magnetoresistive random access memory , optoelectronics , magnetization , nanotechnology , random access memory , optics , physics , medicine , alternative medicine , quantum mechanics , pathology , computer science , computer hardware
Four types of pinned magnetic tunnel junctions (MTJs) with threekeylayer structures of Py/Al2O3/Py,Py/Al2O3/Co,Co/Al2O3/Py,Co/Al2O3/Co were fabricated using a contact shadow mask method and an antiferromagnetically pinned layer of Ir22Mn78.The slit width of the shadow mask is 100μm, and the composition of permalloy is PyNi79Fe21.For example, the MTJs of Co/Al2O3/Co with a tunneling magnetoresistance (TMR) ratio of 17.2%, the junction resistance of 76?Ω, the resistance area product RS of 760?kΩμm2, and the freelayer reversal field of 1114A·m-1 defined as the field where the TMR rises to 50% of the total jump were achieved at the as deposited state at room temperature. Furthermore, when the magnetic field increases from 0 to 1114?A·m-1 the TMR ratio jumps from 0 to 17.2% with one step, which shows that the magnetic field sensitivity of the junction reached at 0.1%/(103A·m-1). While, the TMR vs external filed H curves for the pinned MTJs of Co/Al2O3/Py show a good rectangular shape with a small free-layer reversal filed of 1114?A·m-1. Our exprimental results show that such MTJs can be used to fabricate the magnetic field sensitive sensors or prototype demonstration devices of magnetoresistive random access memory.