What We Learned at ALD 2017

The conference in Denver, USA was the largest yet of this series, with about 900 registrations. Plasma Technology presented and co-authored several posters on both atomic layer etching and deposition. Dr Harm Knoops, our Technical ALD Sales Specialist based at TU Eindhoven, was on the programme committee – several presentations were given by that group.

The ALE (atomic layer etch) poster session on Saturday was very intense! ALE of GaN and AlGaN attracted visitors continuously until the staff began to turn off the lights and the drinks had been put away. Collaboration between Plasma Technology and Lawrence Berkeley Laboratory produced an interesting study of silicon dioxide ALE, using a combination of RF frequencies in a parallel plate configuration. We were very proud that a piece of work done jointly with IMEC on atomic layer etching of silicon, stopping on monolayer MoS2, won the best poster prize. Well done to Markus Heyne (pictured below)! View the poster.

Richard Gottscho gave an excellent plenary talk on atomic layer etching. The importance of substrate temperature control was highlighted, as well as the expected controls on chemical dose and ion bombardment. The binding of chemical species to the surface has low activation energy, low enough that thermal energy is sufficient to alter the surface dose. The wide temperature control range of Plasma Technology ALE equipment, especially its low temperature capability, gives an extra angle to ALE process development.

On the deposition side, selective atomic layer deposition (ALD) competed with spatial ALD for the use of the S-ALD acronym. Selective ALD is a strong focus of academic study, while spatial ALD is heading towards being the method of choice for increasing deposition speed in ALD. This is likely to intensify as applications of ALD pick up, especially if any of the lithium ion battery applications mature. ALD Al₂O₃ improves battery performance, if infiltrated to coat lithium carbonate grains.

The conference moves to Korea in 2018 – watch this space!