Atomic Layer Deposition of Metal Oxide Films on GaAs (100) surfaces

Atomic Layer Deposition is used to deposit HfO2 and TiO2 films on GaAs (100) native oxides and etched surfaces. For the deposition of HfO2 films two different but similar ALD chemistries are used: i) tetrakis dimethyl amido hafnium (TDMAHf) and H2O at 275°C and ii) tetrakis ethylmethyl amido hafnium (TEMAHf) and H2O at 250°C. TiO2 films are deposited from tetrakis dimethyl amido titanium (TDMATi) and H2O at 200°C. Rutherford Back Scattering shows linear film growth for all processes. The film/substrate interface is examined using x-ray photoelectron spectroscopy and confirms the presence of an “interfacial cleaning” mechanism