17th International Conference on Insultating Films on Semiconductors Grenoble, FRANCE, JUN 21-24, 2011
In this paper we present the study of the S-passivation of the Ge gate stack. S-passivation was achieved by using H2S exposure on the clean Ge(1 0 0) surface. Al2O3 was deposited on the Ge/S surface by atomic layer deposition (ALD). The resulting gate stacks were analyzed chemically and electrically. We studied the influence of the ALD oxidant precursor (H2O versus O-3) on the passivation behavior of the gate stack. We observe that for the same surface passivation, the interface depends largely on the oxidant precursor: H2O as a precursor results in a gate stack free of Ge-oxide and the gate stack shows low D-it at the valence band edge. On the other hand, O-3 as a precursor results in a thin GeOxSy), interfacial layer with low D-it at the mid gap and conduction band edge. (C) 2011 Elsevier B.V. All rights reserved.