Equivalent oxide thickness scaling of Al₂O₃/Ge metal-oxide-semiconductor capacitors with ozone post oxidation

Aluminum-oxide films deposited as gate dielectrics on germanium (Ge) by atomic layer deposition (ALD) were post oxidized in an ozone atmosphere. No additional interfacial layer was detected by the high-resolution cross-sectional transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS) measurements made after the ozone post oxidation (OPO) treatment. Decreases in the equivalent oxide thickness of the OPO-treated Al₂O₃/Ge MOS capacitors were confirmed. Furthermore, a continuous decrease in the gate leakage current was achieved with increasing OPO treatment time. The results can be attributed to the film quality having been improved by the OPO treatment.