Effect of an in situ hydrogen plasma pre-treatment on the reduction of GaSb native oxides prior to atomic layer deposition

•H2 plasma exposure removes Sb-oxides, reduces elemental Sb, and increases Ga2O3.•Oxide removal and redistribution highly dependent upon surface temperature.•Surface modification tuned by plasma power, exposure time, and substrate temperature.•Highest capacitance modulation correlated with highest Ga2O3 content.

The influence of an in situ hydrogen plasma pre-treatment on the modification of native oxides of GaSb surfaces prior to atomic layer deposition (ALD) is presented. The effects of varying rf-plasma power, exposure time, and substrate temperature have been characterized by atomic force microscopy (AFM), ex situ X-ray photoelectron spectroscopy (XPS), as well as capacitance-voltage (C-V) measurements on fabricated devices. Results indicate that a completely oxide free surface may not be necessary to produce a good electrical interface with a subsequent ALD Al2O3 dielectric; the most effective hydrogen plasma treatments resulted in the absence of Sb-oxides, a reduction in elemental Sb, and an increase in the Ga2O3 content at the interface. The use of an in situ hydrogen plasma pre-treatment eliminates the need for wet chemical etches and may also be relevant to the deposition of other high-k dielectrics, making it a promising technique for realizing high performance Sb-based MOS-devices.