Improved interfacial quality of GaAs metal-oxide-semiconductor device with NH3-plasma treated yittrium-oxynitride as interfacial passivation layer

摘要

The interfacial and electrical properties of GaAs metal-oxide-semiconductor capacitors with yittrium-oxynitride interfacial passivation layer treated by N-2/NH3-plasma are investigated, showing that lower interface-state density (1.24 x 10(12) cm(-2) eV(-1) near midgap), smaller gate leakage current density (1.34 x 10(-5) A/cm(2) at V-fb + 1 V), smaller capacitance equivalent thickness (1.43 nm), and larger equivalent dielectric constant (24.5) can be achieved for the sample with NH3-plasma treatment than the samples with N-2-/no-plasma treatment. The mechanisms lie in the fact that NH3-plasma can provide not only N atoms, but H atoms and NH radicals to effectively passivate the high-k/GaAs interface, thus less pinning the Femi level at high-k/GaAs interface.