Effect of Annealing on Magnetostrictive Sense Layer for Ultrasensitive Spintronic MEMS Sensor

This paper is about the fabrication of magnetostrictive sense layer for ultrasensitive MEMS pressure sensors using Magnetic Tunnel Junction (MTJ) as sensing element. This spintronic sensing element is fabricated using nanofabrication techniques. The effect of annealing during the fabrication of sense layer of the MTJ and its magnetization change is discussed in this paper. Magnetostriction property of the sense layer is utilised to sense the change in magnetisation due to applied stress. This magnetization change will lead to a change in tunnel magnetoresistance (TMR) which will give the measure of applied pressure. Ni
₈₀
Fe
₂₀
and Co
₂₀
Fe
₆₀
B
₂₀
sense layers are studied and it is found that CoFeB is a promising candidate for the magnetostrictive sense layer. Improvements in TMR can be studied by observing the variations in magnetization change of sense layer leading to a giant gauge factor.