Understanding 'Clean-Up' of III–V Native Oxides During Atomic Layer Deposition Using Bulk First Principles Models
Abstract:The use of III–V materials as the channel in future transistor devices is dependent on removing the deleterious native oxides from their surface before deposition of a gate dielectric. Trimethylaluminium has been found to achieve in situ 'clean-up' of the oxides of GaAs and InGaAs before atomic layer deposition (ALD) of alumina. Here we propose six reaction mechanisms for 'clean-up,' featuring exchange of ligands between surface atoms, reduction of arsenic oxide by methyl groups and desorption of various products. We use first principles Density Functional Theory (DFT) to determine which mechanistic path is thermodynamically favoured based on models of the bulk oxides and gas-phase products. We therefore predict that 'clean-up' of arsenic oxides mostly produces As4 gas. Most C is predicted to form C2H6 but with some C2H4, CH4 and H2O. An alternative pathway is non-redox ligand exchange, which allows non-reducible oxides to be cleaned-up.
Document Type: Research Article
Publication date: September 1, 2011
More about this publication?
- Journal for Nanoscience and Nanotechnology (JNN) is an international and multidisciplinary peer-reviewed journal with a wide-ranging coverage, consolidating research activities in all areas of nanoscience and nanotechnology into a single and unique reference source. JNN is the first cross-disciplinary journal to publish original full research articles, rapid communications of important new scientific and technological findings, timely state-of-the-art reviews with author's photo and short biography, and current research news encompassing the fundamental and applied research in all disciplines of science, engineering and medicine.
- Editorial Board
- Information for Authors
- Subscribe to this Title
- Terms & Conditions
- ingentaconnect is not responsible for the content or availability of external websites