Excellent surface passivation of crystalline silicon by ternary AlxMg1−xOy thin films

A new class of passivation material, ternary Al_xMg_1-xO_y is developed and its surface passivation and interface properties on silicon surfaces are investigated in this study. Super-cycle plasma-enhanced atomic layer deposition is employed to fabricate Al_xMg_1-xO_y thin films and can effectively engineer physical properties of the thin films. Our study also shows that the developed Al_xMg_1-xO_y can provide excellent surface passivation on p-type silicon as indicated by very low S_eff,_max of ~1.8 cm/s after annealing. The observed excellent passivation quality seems to be due to enhanced interface properties (i.e. enhanced Q_eff and D_it) by Mg ion doping into AlO_x.