Electron spin resonance studies of (100)Si/Al2O3/ZrO2 stacks with nm-thick dielectric layers revealed that the Si dangling-bond-type centers, Pb0, Pb1, were prominent defects at the (100)Si/dielectric interface. This Pb0, Pb1 fingerprint indicated that the as-deposited (100)Si/Al2O3 interface was basically Si/SiO2-like. The interfaces were in an enhanced (unrelaxed) stress state which was characteristic of low-temperature Si/SiO2 growth. Based upon the Pb0, Pb1 criterion, standard thermal Si/SiO2 interface properties could be approached by annealing. However, an O2 ambient was required for Si/Al2O3; thus indicating that the initial abruptness of the interface prevented thermal adaptation from occurring until an additional SiOx interlayer had grown. A minimum SiOx interlayer thickness (greater than 0.5nm) appeared to be required.

Si Dangling-Bond-Type Defects at the Interface of (100)Si with Ultrathin Layers of SiOx, Al2O3, and ZrO2. A.Stesmans, V.V.Afanasev: Applied Physics Letters, 2002, 80[11], 1957-9