Al-doped HfO2/In0.53Ga0.47As metal-oxide-semiconductor capacitors

Abstract

Hafnium oxide gate dielectrics doped with a one to two percent of aluminum are grown on In0.53Ga0.47As channels by codeposition of trimethylaluminum (TMA) and hafnium tertbutoxide (HTB). It is shown that the addition of TMA during growth allows for smooth, amorphous films that can be scaled to ∼5 nm physical thickness. Metal-oxide-semiconductor capacitors (MOSCAPs) with this dielectric have an equivalent oxide thickness of 1 nm, show an unpinned, efficient Fermi level movement and lower interface trap densities than MOSCAPs with HfO2 dielectrics grown by sequential TMA/HTB deposition.