Fermi level unpinning of GaSb (100) using plasma enhanced atomic layer deposition of Al2O3

A. Ali, H. S. Madan, A. P. Kirk, D. A. Zhao, D. A. Mourey, M. K. Hudait, R. M. Wallace, T. N. Jackson, B. R. Bennett, J. B. Boos, S. Datta
2010 Applied Physics Letters  
N-type and p-type GaSb metal-oxide-semiconductor capacitors ͑MOSCAPs͒ with atomic-layer-deposited ͑ALD͒ and plasma-enhanced-ALD ͑PEALD͒ Al 2 O 3 dielectrics are studied to identify the optimum surface preparation and oxide deposition conditions for a high quality oxide-semiconductor interface. The ALD Al 2 O 3 / GaSb MOSCAPs exhibit strongly pinned C-V characteristics with high interface state density ͑D it ͒ whereas the PEALD Al 2 O 3 / GaSb MOSCAPs show unpinned C-V characteristics ͑low D it
more » ... . The reduction in Sb 2 O 3 to metallic Sb is suppressed for the PEALD samples due to lower process temperature, identified by x-ray photoelectron spectroscopy analysis. Absence of elemental Sb is attributed to unpinning of Fermi level at the PEALD Al 2 O 3 / GaSb interface.
doi:10.1063/1.3492847 fatcat:rdjkfu7jpna5zbcn4ow4vi5fuu