Ion induced intermixing and consequent effects on the leakage currents in HfO2/SiO2/Si systems

Atomic layer deposited (ALD) samples with layer stacks of HfO2 (3 nm)/SiO2 (0.7 nm)/ Si were subjected to 120 MeV Au ion irradiation at different fluences to study intermixing effects across the HfO2/SiO2 interface. High-resolution Rutherford backscattering spectrometry (HRBS) and X-ray reflectivity (XRR) measurements confirm an increase in the interlayer thickness as a result of SHI induced intermixing effects. Current–voltage (I–V) measurements reveal an order of magnitude difference in the leakage current density between the pristine and irradiated samples. This can be explained by considering the increased physical thickness of interlayer (HfSiO). Furthermore, the samples were subjected to rapid thermal annealing (RTA) process to analyze annealing kinetics.