ABSTRACT
Hafnium oxide (HfO2) films were grown by atomic layer deposition on chemically cleaned p-type Ge and Si substrates with different thicknesses. For the electrical measurements, we fabricated the metal-oxide-semiconductor (MOS) devices with Platinum (Pt) electrode. The capacitance-voltage and current-voltage characteristics were measured on the sandwich structure of Pt/HfO2/substrate. From the C-V measurement and we confirmed that the accumulation capacitance is reduced more significantly in the Si device than Ge device, might be thickness of interfacial layer (IL) at the HfO2/semiconductor. The Ge device exhibited thin interfacial layers than Si device and it is thermally unstable. The measured dielectric constant value is relative high for Ge-devices when compare with Si-devices. Besides, Ge device exhibited similar leakage current as Si devices. Therefore, Ge might be a reliable substrate material for high frequency MOS devices.
