@misc{CuypersFleischmannDorpetal., author = {Cuypers, Daniel and Fleischmann, Claudia and Dorp, Dennis H. von and Brizzi, Simone and Tallarida, Massimo and M{\"u}ller, Matthias and H{\"o}nicke, Philipp and Billen, Arne and Chintala, Ravi and Conard, Thierry and Schmeißer, Dieter and Vandervorst, Wilfried and Elshocht, Sven van and Armini, Silvia and De Gendt, Stefan and Adelmann, Christoph}, title = {Sacrificial Self-Assembled Monolayers for the Passivation of GaAs(100) Surfaces and Interfaces}, series = {Chemistry of Materials}, volume = {28}, journal = {Chemistry of Materials}, number = {16}, issn = {0897-4756}, doi = {10.1021/acs.chemmater.6b01732}, pages = {5689 -- 5701}, abstract = {The use of sacrificial self-assembled monolayers (SAMs) to prepare clean n-type GaAs (100) surfaces without band bending in vacuo is demonstrated. GaAs surface passivation using octadecanethiol SAMs after HCl cleaning is shown to lead to an enhancement of the room-temperature photoluminescence intensity. Synchrotron-radiation photoelectron spectroscopy (SRPES) finds that the interfacial oxide between GaAs and the SAM remains below the detection limit. Evidence for both Ga-S and As-S bonds at the GaAs-thiolate interface is found. The limited thermal stability of the SAM allows the desorption of the alkyl chains by in situ thermal annealing at temperatures above 180 °C, leaving S bonded to Ga behind. The resulting surface contains only a very small amount of O (0.05 ML coverage) and C (about 3\% of the SAM remaining) and shows no band bending with the surface Fermi level close to the conduction band. Atomic layer deposition of Al₂O₃ on this surface occurs via the formation of Al-S bonds without introducing any additional band bending. This indicates that the surface preparation of n-type GaAs (100) using sacrificial octadecanethiol SAMs followed by in situ thermal removal provides a route toward GaAs/oxide interfaces without interfacial oxides and without band bending.}, language = {en} }