Electron spin resonance analysis of interfacial Si dangling bond defects in stacks of ultrathin SiO2, Al2O3, and ZrO2 layers on (100)Si

Abstract Paramagnetic point defects were probed by electron spin resonance in stacks of (1 0 0)Si with nm-thin SiOx, ZrO2, and Al2O3 layers. After hydrogen photodesorption (8.48 eV; 300 K), the Si dangling bond interface centers Pb0, Pb1 appear as prominent defects at all (1 0 0)Si/dielectric interfaces. This Pb0, Pb1 fingerprint, generally unique for the thermal (1 0 0)Si/SiO2 interface, indicates that, while reassuring for the Si/SiOx/ZrO2 case, the as-deposited (1 0 0)Si/Al2O3 interface is basically Si/SiO2-like. The interfaces are under enhanced stress, typical for low temperature Si/SiO2 growth. Standard quality thermal Si/SiO2 interface properties, as exposed by the Pb-type defects (density ∼1×1012 cm−2), may be approached by appropriate annealing (∼650 °C). A high quality (1 0 0)Si/SiO2 type interface, with ultrathin SiO2 interlayer, may be basic to successful application of high-κ metal oxides in Si-based devices.