Atomic Layer Deposition of Al-doped ZrO2 Thin Films for Advanced Gate Stack on III-V Substrates

We have investigated the atomic layer deposition (ALD) on III-V substrates (i.e., GaAs and In0.53Ga0.47As) of Al-doped ZrO2 (Al-ZrO2) films. The aim is to benefit from TMA-based chemistry as adopted in the ALD of Al2O3 and to boost the dielectric constant of the stack. An in situ monitoring of the process with spectroscopic ellipsometry was carried out in order to address the formation of the first few monolayers of the films. The correlation with the structural and chemical characterization provides insights about the interface composition upon ALD. The electrical performances of capacitors fabricated on In0.53Ga0.47As including Al-ZrO2 as gate dielectric exhibits encouraging properties compared to those acquired for Al2O3.