Heteroepitaxy of $$La_2O_3$$ and $$La_{2-x}Y_xO_3$$ on GaAs (111)A by Atomic Layer Deposition: Achieving Low Interface Trap Density

 Title: Heteroepitaxy of $$La_2O_3$$ and $$La_{2-x}Y_xO_3$$ on GaAs (111)A by Atomic Layer Deposition: Achieving Low Interface Trap Density Author: Gordon, Roy Gerald; Wang, Xinwei; Dong, Lin; Zhang, Jingyun; Liu, Yiqun; Ye, Peide D. Note: Order does not necessarily reflect citation order of authors. Citation: Wang, Xinwei, Lin Dong, Jingyun Zhang, Yiqun Liu, Peide D. Ye, and Roy Gerald Gordon. Forthcoming. Heteroepitaxy of $$La_2O_3$$ and $$La_{2-x}Y_xO_3$$ on GaAs (111)A by atomic layer deposition: Achieving low interface trap density. Nano Letters. Full Text & Related Files: Gordon_Heteroepitaxy.pdf (957.7Kb; PDF) Abstract: GaAs metal–oxide–semiconductor devices historically suffer from Fermi-level pinning, which is mainly due to the high trap density of states at the oxide/GaAs interface. In this work, we present a new way of passivating the interface trap states by growing an epitaxial layer of high-k dielectric oxide, $$La_{2–x}Y_xO_3$$, on GaAs(111)A. High-quality epitaxial $$La_{2–x}Y_xO_3$$ thin films are achieved by an ex situ atomic layer deposition (ALD) process, and GaAs MOS capacitors made from this epitaxial structure show very good interface quality with small frequency dispersion and low interface trap densities $$(D_{it})$$. In particular, the $$La_2O_3$$/GaAs interface, which has a lattice mismatch of only 0.04%, shows very low $$D_{it}$$ in the GaAs bandgap, below $$3 × 10^{11} cm^{–2} eV^{–1}$$ near the conduction band edge. The $$La_2O_3$$/GaAs capacitors also show the lowest frequency dispersion of any dielectric on GaAs. This is the first achievement of such low trap densities for oxides on GaAs. Published Version: doi:10.1021/nl3041349 Terms of Use: This article is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#OAP Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:10265395 Downloads of this work: