Saturday, October 31, 2015

Open Source Review on Flash-Enhanced ALD from ALD Lab Dresden

Here is a fantastic Open Source review from ALD Lab Dresden (IHM, TU Dresden) on Flash Enhanced ALD coming from one of the probably coolest ALD tools today - The FHR.Star.100-ALD-PECVD-FLA (see below). Not all capabilities are reviled in this paper so you should stay tuned for more from Thomas Henke.

Flash-Enhanced Atomic Layer Deposition: Basics, Opportunities, Review, and Principal Studies on the Flash-Enhanced Growth of Thin Films

Thomas Henke, Martin Knaut, Christoph Hossbach, Marion Geidel, Lars Rebohle, Matthias Albert, Wolfgang Skorupa, Johann W. Bartha
doi: 10.1149/2.0301507jss ECS J. Solid State Sci. Technol. volume 4, issue 7, P277-P287 

Within this work, flash lamp annealing (FLA) is utilized to thermally enhance the film growth in atomic layer deposition (ALD). First, the basic principles of this flash-enhanced ALD (FEALD) are presented in detail, the technology is reviewed and classified. Thereafter, results of our studies on the FEALD of aluminum-based and ruthenium thin films are presented. These depositions were realized by periodically flashing on a substrate during the precursor exposure. In both cases, the film growth is induced by the flash heating and the processes exhibit typical ALD characteristics such as layer-by-layer growth and growth rates smaller than one Å/cycle. The obtained relations between process parameters and film growth parameters are discussed with the main focus on the impact of the FLA-caused temperature profile on the film growth. Similar, substrate-dependent growth rates are attributed to the different optical characteristics of the applied substrates. Regarding the ruthenium deposition, a single-source process was realized. It was also successfully applied to significantly enhance the nucleation behavior in order to overcome substrate-inhibited film growth. Besides, this work addresses technical challenges for the practical realization of this film deposition method and demonstrates the potential of this technology to extend the capabilities of thermal ALD.

Configuration of the FEALD process station comprising the flash lamp unit and the cross-flow deposition reactor. The small arrows illustrate the gas flow directions. 

The FHR.Star.100-ALD-PECVD-FLA - a comboned processing tool for ALD, PECVD and Rapid Thermal Annealing of 100 mm Wafers