Improving the ALD-grown Y 2 O 3 /Ge interface quality by surface and annealing treatments

Metal Oxide Semiconductor capacitors are investigated, employing ALD grown Y 2 O 3 as gate dielectric, and n-type (1 0 0) germanium as channel substrate. The effect of post deposition annealing (PDA) in oxygen and forming gas atmosphere using a thin catalytically acting platinum (Pt)-layer on the Y 2 O 3 /Ge interface is electrically analyzed for buffered hydrofluoric (BHF) and thermally pre-treated Ge-surfaces. The Pt-assisted PDA ensures even for BHF pre-treated samples very low values for the interface trap density D it of 1.55 × 10 11 eV −1 cm −2 and low leakage current densities J of −9 A/cm 2 outperforming conventional PDA treatments. The interfacial formation of GeO 2 and yttrium germanate after PDA is proven by using X-ray Photoelectron Spectroscopy measurements.