Substrate dependence of surface passivation using atomic layer deposited dielectrics

This paper presents low temperature surface passivation using atomic layer deposited aluminium oxide (Al₂O₃) and hafnium oxide (HfO₂) thin films on different silicon substrates. Al₂O₃ and HfO₂ thin films were deposited on p (111) and p (100) Si substrates with different ALD cycles, respectively. Capacitance-voltage (CV) measurement was executed on Al/oxide/Si structures. CV measurements were used to determine the thickness of dielectric layers and threshold voltage (V_th) of Al/oxide/Si structures. The CV experiments suggest that the growth rate of ALD oxides is higher on (111) Si surface than that of the (100) substrate. Further, it was observed that the fixed charge density at the interface of Al₂O₃/Si and HfO₂/Si is larger for (100) Si surface.