Atomic layer deposition of high-κ dielectric for germanium MOS applications - substrate

In this letter, we present the use of atomic layer deposition (ALD) for high-κ gate dielectric formation in Ge MOS devices. Different Ge surface cleaning methods prior to high-κ ALD have been evaluated together with the effects on inserting a Ge oxynitride (GeO_xN_y) interlayer between the high-κ layer and the Ge substrate. By incorporating a thin GeO_xN_y interlayer, we have demonstrated excellent MOS capacitors with very small capacitance-voltage hysteresis and low gate leakage. Physical characterization has also been done to further investigate the quality of the oxynitride interlayer.