Date: Tuesday, April 24, 2012
Time: 10:00 am
Location: PHYS 401
Surface reactions during the atomic layer deposition of high‑κ dielectrics on GaAs surfaces
Atomic layer deposition (ALD) of high dielectric constant (high‑κ) gate dielectrics on III-V semiconductors has been a subject of great interest and has shown promising applications in metal-oxide-semiconductor field effect transistors (MOSFET). However, the mechanism for the deposition of high‑κ gate dielectrics on III-V semiconductors is still not clear. The purpose of the proposed research is to study the surface reactions of a series of metal organic precursors and H2O on GaAs surfaces during ALD. The adsorption and reaction of HfO2 precursors, including tetrakis(dimethylamino)hafnium [Hf(N(CH3)2)4] (TDMAH), tetrakis(diethylamino)hafnium [Hf(N(C2H5)2)4] (TDEAH) and tetrakis(ethylmethylamino)hafnium [Hf(N(CH3C2H5)4] (TEMAH), TiO2 precursor tetrakis(dimethylamino)titanium [Ti(N(CH3)2)4] (TDMAT) and Ta2O5 precursor pentakis(dimethylamino)tantalum [Ta(N(CH3)2)5] (PDMAT) and H2O on GaAs (100) surfaces will be investigated by in-situ attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). This research will improve our understanding of the surface reaction mechanisms during the ALD of high‑κ gate dielectrics on III-V semiconductors.