Dielectric tunnel parameters of CoFe/Al-O/CoFe in MTJ for 1T1MTJ MRAM applications

Dielectric tunnel parameters of thin insulating layer in MTJ of MRAM cell are measured and analyzed. General mathematical derivations for dielectric tunnel parameters in bright and dark region of MTJ cell are derived. Dielectric tunnel offset voltage in bright region of MTJ may relate to the screening effect of uneven dipole charge layer by external ramping bias and the spin-accumulated magnetization dipole layer by nonlinear tunnel current. The symmetry variation of dielectric tunnel charge in dark region of MTJ demonstrates a good balanced charge-conserved ferromagnetic plate capacitor. Parameters extraction and equivalent circuit model of dielectric tunnel capacitance C and resistance R from current-voltage curve for data 0 and 1 during 1T1MTJ read mode are illustrated.