Reconstruction at the interface of one cycle of trimethylaluminum and water on GaAs(111)A-2?2 from atomic layer deposition
Journal
Applied Physics Express
Journal Volume
8
Journal Issue
12
Date Issued
2015
Author(s)
Abstract
During the initial stage of atomic layer deposition, the exposure of a GaAs(111)A-2×2 surface to trimethylaluminum (TMA) leads to occupying a Gavacancy site on the surface by a chemisorbed As-bonded aluminum with the loss of all methyl ligands. The water purge disrupts physisorbed TMA and initiates the growth of Al2O3. The subsequent growth of Al2O3 does not result in the oxidation of As, Ga, or Al in the Ga vacancy. The reconstructed Ga atoms retain the bulk-terminated positions resulting in a dangling bond, and all As atoms become four-fold coordinated. The correlation of an interfacial electronic structure with an electric performance is discussed for Al2O3 on GaAs(001)-2×4 and GaAs(001)-4×6.
SDGs
Type
journal article