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

• Using yittrium-oxynitride as interfacial passivation layer to get a good interface
• Using NH3 or N2 plasma to treat YON interfacial passivation layer and passivate the interface
• The sample treated by NH3 plasma shows better performance.

The interfacial and electrical properties of GaAs metal-oxide-semiconductor capacitors with yittrium-oxynitride interfacial passivation layer treated by N2 −/NH3-plasma are investigated, showing that lower interface-state density (1.24 × 1012 cm− 2 eV− 1 near midgap), smaller gate leakage current density (1.34 × 10− 5 A/cm2 at Vfb + 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 N2 −/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.