Professor Steven George (University of Colorado, Boulder) and InRedox presented results of recent collaboration on spatial Atomic Layer Deposition at the 15th International Conference on Atomic Layer Deposition (ALD 2015, Portland, USA) on June 29, 2015.

Spatial Atomic Layer Deposition (S-ALD) is based on spatial separation of precursors instead of time based separation as in ZnO ALD inside 100 nm pores of AAOconventional ALD, which facilitates high throughput processing of large substrates. In this work, a flexible nanoporous substrates from Anodic Aluminum Oxide (AAO) on Al foil produced by InRedox were attached to a rotating cylinder reactor.  Performing ALD of ZnO into AAO with a wide range of pore diameter and pore length, gas transport processes inside the pores were evaluated and optimal reactant pulse duration and rotating speed for conformal coating of the high aspect ratio pores were established.

Due to its highly uniform pore structure and flexibility, AAO nanotemplates on Al foil are an ideal model substrate for evaluating the potential of S-ALD for conformal coating of porous substrates for many applications, such as electrodes for Li batteries and supercapacitors, photovoltaic materials, catalytic substrates and others.

“ZnO ALD Coverage in the Pores of Anodic Aluminum Oxide Membranes Deposited Using Spatial ALD”, K. Sharma1, D. Routkevitch2, N. Varaksa2 and S. M. George1,3;  1Dept. Chem. and Biochem., 3Dept. Mech. Eng., University of Colorado, Boulder, CO, USA; 2InRedox LLC, Longmont, CO, USA.