Wet chemical cleaning effect on the formation of ultrathin interfacial layer between Germanium (Ge) and high-k dielectric

This paper investigates and discusses the effect of wet chemical cleaning; Hydrochloric Acid (HCl) and Hydrofluoric Acid (HF) to the growth of interfacial layer between high-k material (Al2O3) and Ge (100) surface. Characterization and morphology techniques using Field Emission Scanning Electron Microscope (FESEM) was carried out to determine the thickness of interfacial layer between Al2O3 and Ge (100) surface. Results of this study showed that an HF treatment gives a rougher surface of Al2O3 than HCl treatment. Both wet chemical cleaning resulted with step and terrace trend of Al2O3 and interfacial layer. This may be due to initial Ge surface just after HF cleaning is rougher than the initial Ge surface after HCl cleaning.