The Interfacial Quality of HfO2 on Silicon with Different Thicknesses of the Chemical Oxide Interfacial Layer

We studied the effects of the thickness variation of the chemical oxide interfacial layer (IL) on the interfacial quality of the HfO2/Si system in this paper. Metal-oxide-semiconductor (MOS) capacitors using the HfO2/IL gate oxide stack were fabricated using the Ni/Ti metal gate. The capacitance-voltage and ellipsometry measurements suggest that the chemical oxide interfacial layer of similar to 0.45 nm is the minimum requirement for atomic layer deposition growth of high quality HfO2 on silicon and thicker chemical oxide ILs (> 0.45nm) result in better interfaces for HfO2 MOS structures with equivalent oxide thicknesses of < 1 nm. (c) 2010 The Electrochemical Society. [DOI: 10.1149/1.3483789] All rights reserved.