Nondestructive diagnostics of high-k dielectrics for advanced electronic devices

The authors present novel results on the interface between silicon and the high- oxides Al2O3 and HfO2 grown by atomic layer deposition. The determination of the thickness of the interfacial layer between oxide and Si (100)is crucial to the evaluation of the performances of devices based on high- k dielectrics. They find through hard x-ray photoemission spectroscopy (HaXPES) that no interfacial layer forms between Al2O3 and Si(100) whereas almost one monolayer forms between HfO2 and Si(100). HaXPES does not involve any destructive procedure nor any sample preparation. High-energy photoemission could therefore be widely employed for the characterization of real devices.