Effect of ALD Processes on Physical and Electrical Properties of HfO₂ Dielectrics for the Surface Passivation of a CMOS Image Sensor Application

The surface passivation of a CMOS image sensor (CIS) is highly beneficial for the overall improvement device performance. We employed thermal atomic layer deposition (T-ALD) and plasma enhanced (PE-ALD) techniques 20 nm HfO2 as well stacked with 3 5 Al2O3 thin films. HfO2/Si Al2O3/HfO2/Si metal-oxide-semiconductor structures were used to analyze fixed charge density (Qf) interface trap (Dit). as-synthesized samples show high Dit Qf values (1012 cm-2eV-1) minority carrier lifetime 15-300 μs. finite-difference time-domain simulation high-k dielectrics confirmed that (top)/HfO2 expected higher quantum efficiency CIS application. effect vacuum annealing (VA) forming gas (FGA) treatments succeeded decomposition increase in lifetime. H2 ambient FGA showed remarkable decrease values. To improve performance after passivation, we an Al2O3/HfO2 bilayer structure, which low 1011 cm-2eV-1 ~3,700 μs 400 °C 30 min FGA. believe this strategy will pave way future technology regarding development lower defective superior