A new ALD reactor is under construction in our lab. The previous tubular reactor system (seen at right in the photo) produced excellent alumina and ZnO films, but was a bit problematic in terms of its utility for studying reactor dynamics due primarily to the large volume of the reactor process tube.

This new reactor, with its much-reduced volume, should provide for better precursor purging and access to the wafer itself. Key elements in its design include the optical ports and two supports seen in this figure – they are to be used for in-situ ellipsometry that has the potential to quantify ALD deposition dynamics in real-time.

This reactor was designed by Dr. Vivek Dwivedi, an alumnus of our research group, currently at the NASA Goddard Space Flight Center here in Maryland.

Our recent paper Anomalously high alumina atomic layer deposition growth per cycle during trimethylaluminum under-dosing conditions by Hossein Salami, Andrew Poissant and Raymond A. Adomaitis has made the “Most Read List for November 2016” of JVST A. In this paper we report on unexpectedly high atomic layer deposition (ALD) growth per cycle of spatially uniform alumina films during underdosing of the aluminum precursor – precisely the opposite of what one would expect. We postulated a potential deposition mechanism explaining this unusual growth. Follow-up work on an alternative reactor-specific hypothesis explaining this phenomenon is underway.