Magnetoresistance ratio in magnetic tunnel junction with silicon diffused MgO barrier

Abstract

We demonstrated a magnetic tunnel junction (MTJ) consisting of Fe/MgO-Si-MgO/Fe. Si layer was deposited at room temperature and at 700 °C; when deposited at 700 °C, Si diffused into the MgO layer. The MTJ with silicon deposited at 700 °C attained high MR ratios of up to 38.7 and 2.9% at t Si = 0.19 and 1.3 nm, respectively. Low-temperature measurements established that the temperature dependence of the MR ratio and resistance between MTJs with and without diffused silicon are significantly different. This behavior confirms that the Si-MgO channel acts as an impurity semiconductor in the MTJ.